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Wyszukujesz frazę "graphite" wg kryterium: Temat


Tytuł:
The effect of changing graphitization temperature toward bio-graphite from Palm Kernel Shell
Autorzy:
Othman, Rapidah
Kamal, Afiqah Samsul
Jabarullah, N. H.
Powiązania:
https://bibliotekanauki.pl/articles/1839526.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
produkcja grafitu
grafitowy materiał węglowy
jakość grafitu
production of graphite
quality of graphite
graphite carbon material
Opis:
This paper focuses on the relationship between heat treatment temperature toward structural transformation from amorphous carbon to highly graphitic carbon material during a production stage.The following report discusses a simple strategy to convert the palm kernel shell (PKS) into highly crystalline, high quality graphite via simple two-step process. The production involves impregnation of catalyst followed by thermal treatment. Both XRD and Raman spectroscopy allowed the observation of microstructural change of the prepared sample at temperature ranging from 1000°C to 1400°C using Ferum catalyst. From XRD pattern it can be observed that as graphitization temperature increased, the degree of graphitization also increased. Overall sample prepared at higher temperature 1400°C shows a higher degree of graphitization. PKS sample graphitized at 1400°C with the aid of Ferum catalyst shows a sharp intensified peak at 2θ = 26.5° reflecting formation of highly crystalline graphite structure. Raman spectrum also suggests similar results to XRD in which PKS-1400 shows the presence of large amount of graphitic structure as the value of (Id/Ig) ratio is lower than in other samples. HRTEM analysis visibly shows define lattice fringe, which further confirms the structural transformation from amorphous to highly ordered graphitic carbon structure. Overall, good quality graphitic carbon structure from Palm Kernel shell was succesfully synthesised via utilization of PKS, Ferum catalsyt and heat treatment method.
Źródło:
Production Engineering Archives; 2021, 27, 2; 124-129
2353-5156
2353-7779
Pojawia się w:
Production Engineering Archives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of changing graphitization temperature toward bio-graphite from Palm Kernel Shell
Autorzy:
Othman, Rapidah
Kamal, Afiqah Samsul
Powiązania:
https://bibliotekanauki.pl/articles/1839543.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
produkcja grafitu
grafitowy materiał węglowy
jakość grafitu
production of graphite
quality of graphite
graphite carbon material
Opis:
This paper focuses on the relationship between heat treatment temperature toward structural transformation from amorphous carbon to highly graphitic carbon material during a production stage.The following report discusses a simple strategy to convert the palm kernel shell (PKS) into highly crystalline, high quality graphite via simple two-step process. The production involves impregnation of catalyst followed by thermal treatment. Both XRD and Raman spectroscopy allowed the observation of microstructural change of the prepared sample at temperature ranging from 1000°C to 1400°C using Ferum catalyst. From XRD pattern it can be observed that as graphitization temperature increased, the degree of graphitization also increased. Overall sample prepared at higher temperature 1400°C shows a higher degree of graphitization. PKS sample graphitized at 1400°C with the aid of Ferum catalyst shows a sharp intensified peak at 2θ = 26.5° reflecting formation of highly crystalline graphite structure. Raman spectrum also suggests similar results to XRD in which PKS-1400 shows the presence of large amount of graphitic structure as the value of (Id/Ig) ratio is lower than in other samples. HRTEM analysis visibly shows define lattice fringe, which further confirms the structural transformation from amorphous to highly ordered graphitic carbon structure. Overall, good quality graphitic carbon structure from Palm Kernel shell was succesfully synthesised via utilization of PKS, Ferum catalsyt and heat treatment method.
Źródło:
Production Engineering Archives; 2021, 27, 2; 124-129
2353-5156
2353-7779
Pojawia się w:
Production Engineering Archives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania nad procesem utleniania grafitu mieszaninami utleniającymi w kwasach nieorganicznych
Survey of graphite oxidation methods using oxidizing mixtures in inorganic acids
Autorzy:
Ciszewski, M.
Mianowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1216851.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
grafit
utlenianie
tlenek grafitu
eksfoliacja
graphite
oxidation
graphite oxide
exfoliation
Opis:
W artykule porównano trzy najpopularniejsze metody chemicznego utleniania grafitu zaproponowane przez Brodie, Staudenmaiera i Hummersa. Grafit poddano utlenianiu w mieszaninach silnych utleniaczy i stężonych kwasów nieorganicznych zgodnie z przepisami podanymi w literaturze. W zależności od stosowanej metody utlenianie prowadzono od kilku do kilkuset godzin. Produkty przebadano pod kątem zawartości tlenu, stosunku C/O oraz analizy jakościowej i ilościowej grup funkcyjnych. Na podstawie przeprowadzonych badań ustalono, że najlepiej utleniony grafit można uzyskać stosując najbardziej czasochłonną metodę Brodie. Metoda Staudenmaiera daje dobrze utleniony grafit i możliwość prowadzenia ciągłego procesu, ale wymaga długiego czasu utleniania. Metoda Hummersa jest najkrótsza, jednak pozostawia sporą ilość nieutlenionych atomów węgla.
Three most popular methods of chemical oxidation of graphite proposed by Brodie, Staudenmaier and Hummers has been compared here. Synthetic graphite has been oxidized using strong chemical oxidizing agents in highly-concentrated inorganic acids. Reaction time varied from several to several hundred hours depending on the applied method. Products were characterized with respect to the oxygen content, C/O ratio, full qualitative and quantitative analysis of the oxygencontaining groups. Based on these experiments it was determined that the most oxidized graphite was obtained using the Brodie method. In case of Staudenmaier method, that can be carried out in single step, well-oxidized graphite can be obtained but much longer oxidation time is required. Method proposed by Hummers is the shortest but graphite oxide possesses a plenty of unoxidized carbon atoms.
Źródło:
Chemik; 2013, 67, 4; 267-274
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Formation, Properties and Use of Dispersed Iron-Graphite Metallurgical Waste
Autorzy:
Dan, Leonid
Maslov, Vladimir
Trofimova, Larysa
Cios, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/2172384.pdf
Data publikacji:
2022
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
dispersed iron-graphite waste
graphite
iron oxides
specific saturation magnetization
magnetizing annealing
carbothermal self-reduction
magnetic graphite
Opis:
Dispersed wastes containing graphite, iron, and its oxides, getting into the air and accumulating in landfills, cause serious harm to human health and the environment. Moreover, even if the issue of the localization of these wastes has been solved successfully, their disposal has not yet been fully organized. In the present study, a systematic analysis of the dispersed iron-graphite waste (IGW) conditions for the formation at metallurgical enterprises, their structure, and their properties were carried out. In this case, special attention is focused on the electrophysical properties: specific saturation magnetization and volume resistivity. The presence of magnetic properties in IGW, combined with low electrical resistivity, makes IGW a promising and inexpensive raw material for obtaining cheap composite materials with radio shielding and radio absorbing properties in the microwave range. As a result of the research, effective ways of improving the magnetic properties of IGW by high-temperature treatment were obtained. The practical result of the research was the development and implementation of a technological scheme of dispersed IGW complex processing, which makes it possible to solve a twofold task – to exclude the ingress of iron-graphite wastes into the environment and to obtain a cheap material for protection against microwave radiation.
Źródło:
Journal of Casting & Materials Engineering; 2022, 6, 4; 81--92
2543-9901
Pojawia się w:
Journal of Casting & Materials Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Bismuth and Rare Earth Elements on Graphite Structure in Different Section Thicknesses of Spheroidal Graphite Cast Iron Castings
Autorzy:
Glavas, Z.
Strkalj, A.
Maldini, K.
Kozina, F.
Powiązania:
https://bibliotekanauki.pl/articles/353810.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spheroidal graphite cast iron casting
graphite structure
bismuth
rare earth elements
microstructure
Opis:
Effects of additions of 0.00064, 0.001 and 0.0042 wt.% Bi on the graphite structure in the section thicknesses of 3, 12, 25, 38, 50, 75 and 100 mm of spheroidal graphite cast iron castings containing 2.11 wt.% Si and rare earth (RE) elements (Ce + La + Nd + Pr + Sm + Gd) in the range from 0.00297 to 0.00337 wt.% were analyzed in this paper. Addition of Bi was not necessary for obtaining high nodule count and nodularity higher than 80% in section thicknesses of 3, 12 and 25 mm. RE elements showed a beneficial effect on the nodule count and nodularity in these sections. Nodularity was below 80% in section thicknesses of 38, 50, 75 and 100 mm when Bi was not added. Detrimental effect of RE elements on graphite morphology in these sections was neutralized by adequate addition of Bi. Addition of 0.001 wt.% Bi (ratio of RE/Bi = 3.27) was enough to achieve nodularity above 80% in the section thickness of 38 mm. Nodularity was increased above 80% in section thicknesses of 50, 75 and 100 mm by addition of 0.0042 wt.% Bi (ratio of RE/Bi = 0.78). At the same time, Bi significantly increased the nodule count. Nodularity above 80% and the high nodule count in the section thicknesses of 75 and 100 mm were also achieved by using an external metallic chill in the mold. In this case, addition of Bi was not required.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1547-1553
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The problem of performance life of structural elements under the conditios of thermal fatigue
Zagadnienie trwalosci elementow konstrukcyjnych pracujacych w warunkach zmeczenia cieplnego
Autorzy:
Pytel, A.
Pysz, S.
Powiązania:
https://bibliotekanauki.pl/articles/792563.pdf
Data publikacji:
2011
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
spheroidal graphite cast iron
flake graphite cast iron
vermicular graphite cast iron
agricultural casting
computer simulation
mechanical property
thermal fatigue
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2011, 11
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of graphite impact on the thermal conductivity of the solidified grout
Autorzy:
Śliwa, T.
Kowalski, T.
Stryczek, S.
Wiśniowski, D.
Bieda, A.
Piwowarczyk, S.
Beszłej, J.
Naklicki, M.
Sapińska-Śliwa, A.
Powiązania:
https://bibliotekanauki.pl/articles/298729.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
graphite
thermal conductivity
geothermal energy
Opis:
The fast development of low-temperature geothermal energy affects the search for newer and newer solutions and materials used in the construction of borehole heat exchangers. One of the most important factors affecting the correct operation of heat pump systems with borehole heat exchangers is appropriately selected solidified grout. Solidifies grout has to be characterized by the highest thermal conductivity and good sealing borehole heat exchangers. The paper will present the impact of graphite on the thermal conductivity of solidified grout.
Źródło:
AGH Drilling, Oil, Gas; 2017, 34, 4; 811-820
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanisms for the improved flotation of inherently hydrophobic graphite in electrolyte solution
Autorzy:
Lai, Q.
Liao, Y.
Liu, Z.
He, Y.
Zhao, Y.
Powiązania:
https://bibliotekanauki.pl/articles/110761.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
graphite
low-grade
electrolyte
Opis:
It is well documented that unavoidable ions in a pulp such as Mg2+, Ca2+, and K+ have a significant effect on the interaction for particles, especially for flotation of metallic sulfide minerals and clay minerals. In this study, the effect of electrolytes on the flotation of inherently hydrophobic mineral-graphite was studied. It was found that the zeta potential showed a dramatic decrease, and the reagent adsorption capacity of mineral enhanced in the present of electrolytes. The possible mechanism responsible for improved recovery was investigated by electrokinetic, surface tension and ions adsorption tests. It is likely that the hydrophobic force is stronger than the electrostatic force due to the reduced potential of graphite. This might be in favor of the formation of hydrophobic oil film leading to an increase in the graphite floatability. The experiments provided a new spectacle to study inherently hydrophobic mineral processing with electrolyte solution.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 944-954
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Graphite expanded as a film-forming material on a steel surface
Grafit ekspandowany jako materiał tworzący warstewkę na stalowym podłożu
Autorzy:
Rewolińska, A.
Perz, K.
Kinal, G.
Powiązania:
https://bibliotekanauki.pl/articles/190601.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
expanded graphite
steel
reciprocating
model
graphite layer
grafit ekspandowany
stal
ruch posuwisto-zwrotny
warstwa grafitu
Opis:
The results of observational studies of the emerging graphite film on the steel surface are presented. The association – steel pin and graphite element – reciprocating motion was employed. The results show the possible mechanism of graphite film formation for the various stages of association work under various operating conditions. For a water-impregnated graphite element, the film forming process takes place faster than for a dry element.
Przedstawiono wyniki badań obserwacyjnych powstającej warstewki grafitowej na stalowym podłożu. Skojarzenie pracowało w układzie stalowy trzpień poruszający się ruchem posuwisto-zwrotnym po elemencie wykonanym z grafitu ekspandowanego. Wyniki badań przedstawiają możliwy mechanizm powstawania warstewki grafitowej na poszczególnych etapach pracy skojarzenia, w różnych warunkach pracy. Dla elementu grafitowego nasączonego wodą proces formowania się warstewki zachodzi szybciej niż dla elementu suchego.
Źródło:
Tribologia; 2017, 275, 5; 81-85
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the Effect of Solidification Time and Addition Amount of Inoculation on Microstructure and Hardness in Lamellar Graphite Cast Iron
Autorzy:
Çolak, Murat
Uslu, Emin
Teke, Çağatay
Şafak, F.
Erol, Ő.
Erol, Y.
Çoban, Y.
Yavuz, M.
Powiązania:
https://bibliotekanauki.pl/articles/2203933.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
lamellar graphite
graphite cast iron
inoculation
solidification time
modeling
grafit
żeliwo
wszczepienia
czas krzepnięcia
modelowanie
Opis:
Material suppliers typically recommend different additive amounts and applications for foundry practices. Therefore, even in the production of the same standard materials, different results may be obtained from various production processes on different foundry floors. In this study, the liquid metal prepared with the addition of different proportions of a FeSi-based inoculation, which is most commonly used in foundries in the production of a cast iron material with EN-GJL-250 lamellar graphite cast iron, was cast into sand molds prepared with a model designed to provide different solidification times. In this way, the optimization of the inoculation amounts on the casting structure for different solidification times was investigated. In addition, hardness values were determined depending on solidification time in varying amounts of inoculation additions. SolidCast casting simulation software was used to determine the casting model geometry and solidification time. In the scope of the study, sand casting, modeling, microstructure analysis, image analysis, microstructure analysis, and hardness tests techniques were used. When the results are examined, the required amount of inoculation for the optimal structure is optimized for the application procedure depending on the casting module and the solidification time.
Źródło:
Archives of Foundry Engineering; 2022, 22, 4; 24--33
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recovery mechanisms of sericite in microcrystalline graphite flotation
Autorzy:
Li, H.
Ou, L.
Feng, Q.
Chang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/110055.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
microcrystalline graphite
sericite
flotation
entrainment
entrapment
Opis:
Sericite is the main contaminant of concentrate in commercial microcrystalline graphite ore flotation. It was necessary to identify its recovery mechanisms so that the appropriate solution can be selected. In this study, the influence of sericite on flotation selectivity of microcrystalline graphite ore and its recovery mechanisms were investigated. Artificial mixtures flotation test suggested that sericite seriously reported into concentrate leading to poor flotation selectivity of microcrystalline graphite ore. However, the aggregation/dispersion behavior of artificial mixtures indicated that a large repulsive energy existed between sericite and microcrystalline graphite particles at pH 7.4, and sericite was not likely to report into graphite concentrate by slime coating. The results obtained from contact angle measurements and a technique of Warren showed that the floated sericite reached the froth via a combination of both entrainment and entrapment mechanisms, not via true flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 2; 387-400
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observation of spheroidal graphite in ductile cast iron by TEM
Charakterystyka grafitu w żeliwie sferoidalnym techniką transmisyjnej mikroskopii elektronowej
Autorzy:
Hara, T.
Maekawa, T
Terayama, K
Kawabata, T.
Ikeno, S.
Matsuda, K.
Powiązania:
https://bibliotekanauki.pl/articles/354792.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ductile cast iron
spheroidal graphite
TEM
FIB method GRAPHITE
grafit sferoidalny
technika FIB
transmisyjna mikroskopia elektronowa
Opis:
The microstructure of spheroidal graphites in ductile cast iron (FCD450) was investigated by TEM using cross sectional TEM samples prepared by FIB method. The spheroidal graphite consisted of many small areas, and all of these areas were indexed as the graphite structure and just carbon peak was detected from there.
Mikrostruktura sferoidalnych wydzieleń grafitu w żeliwie sferoidalnym (FCD450) badana była przy użyciu transmisyjnej mikroskopii elektronowej i cienkich folii przygotowanych technika FIB. Grafit sferoidalny składał się z wielu małych obszarów i stwierdzono, że wszystkie te obszary mają strukturę grafitu i wykryto tylko pik od wegla.
Źródło:
Archives of Metallurgy and Materials; 2013, 58, 2; 431-432
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the activity of irradiated graphite in the Ignalina Nuclear Power Plant RBMK-1500 reactor
Autorzy:
Ancius, D.
Ridikas, D.
Remeikis, V.
Plukis, A.
Plukiene, R.
Cometto, M.
Powiązania:
https://bibliotekanauki.pl/articles/148874.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
modeling
activation analysis
radioactive waste
graphite
Opis:
Ignalina NPP Unit 1 with the RBMK-1500 type reactor enters the preparatory stage for its decommissioning. A big volume of graphite has to be dismantled and managed. This paper evaluates the composition of radionuclides in irradiated graphite on the basis of the calculation scheme with computer codes MCNPX and CINDER'90. Full scale calculations take into account the whole energy spectrum of neutrons, the spatial neutron flux in different reactor structures and the impurities of RBMK-1500 graphite measured by two independent methods. Principal contributors to the total activity as well as other radionuclides important from the radiological point of view are identified. The uncertainties of such calculations are discussed.
Źródło:
Nukleonika; 2005, 50, 3; 113-120
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mineralogical examination of graphite (?) pottery : example – valley settlement in Thunau am Kamp, Lower Austria.
Badania mineralogiczne ceramiki grafitowej (?) : przykład – stanowisko dolinne w Thunau am Kamp, Dolna Austria
Autorzy:
Pawlikowski, M.
Karwowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/343995.pdf
Data publikacji:
2017
Wydawca:
nakł. Maciej Pawlikowski
Tematy:
mineralogy
pottery
graphite
mineralogia
ceramika
grafit
Opis:
This article presents the results of mineralogical and petrographical research of so called graphite pottery. The La Tène culture pottery samples from the valley settlement in Thunau am Kamp were tested. Stereoscopic, polarized and Raman microscopy methods were used in the studies. In addition to examination of graphite from archaeological pottery, Carboniferous Age coal was tested as a potential additive in the La Tène culture pottery masses. Studies were also carried out on graphites from a Bohemian deposit in Český Krumlov, not far from the La Tène culture settlement area of Lower Austria. Another examination included contemporary pottery masses made from local raw materials with natural carbon additives, fired at 750° C in both oxidizing and reducing atmosphere. It was determined that the studied pottery contains coal (probably from Carboniferous Age), not graphite. Due to firing of pottery in reducing atmosphere, it did not burn and did not turn into graphite. "Counterfeit" ceramic pots have been found at the site of Thunau, with only a dark surface layer containing a carbon additive.
Artykuł prezentuje wyniki badań mineralogicznych i petrograficznych ceramiki grafitowej. Wykonano badania próbek ceramiki kultury lateńskiej pochodzących ze stanowiska dolinnego w Thunau am Kamp w Dolnej Austrii. Oprócz badań grafitu (?) z ceramiki archeologicznej wykonano badania węgli kamiennych wieku karbońskiego jako potencjalnego dodatku do mas garncarskich kultury lateńskiej. Wykonano także badania grafitów z czeskiego złoża w Czeskim Krumlovie. Przeprowadzono także badania współczesnych mas garncarskich wykonanych z dodatkami węgla, które to masy wypalono w 750o C zarówno w utleniającej jak i redukcyjnej atmosferze. W badaniach stosowano metody mikroskopii stereoskopowej, polaryzacyjnej jak tez mikroskopii ramanowskiej.
Źródło:
Auxiliary Sciences in Archaeology, Preservation of Relics and Environmental Engineering; 2017, 23; 1-10
1689-6742
Pojawia się w:
Auxiliary Sciences in Archaeology, Preservation of Relics and Environmental Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and noise analysis of polymer graphite cathode
Autorzy:
Knápek, A.
Horáček, M.
Chlumská, J.
Kuparowitz, T.
Sobola, D.
Šikula, J.
Powiązania:
https://bibliotekanauki.pl/articles/220760.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
field emission
polymer graphite
noise analysis
Opis:
The paper deals with the preparation and measurement of an experimental polymer graphite cathode that seems to be a promising and cheap source of electrons utilizing cold field-emission in high- and ultra-high vacuum. Polymer graphite seems to be a proper material as it contains a large amount of hybridized carbon with a low degree of surface oxidation and silicon monoxide (SiO). Within the frame of this work, a special experimental method of tip preparation has been designed and tuned. This method is based on ion milling inside a dual-beam electron microscope enabling to obtain ultra-sharp tips of a diameter smaller than 100 nm with a predefined opening angle. The charge transport within experimental samples is evaluated based on results provided by the noise spectroscopy of the total emission current in the time and frequency domains.
Źródło:
Metrology and Measurement Systems; 2018, 25, 3; 451-458
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Understanding the collection behavior of gangue minerals in fine flake graphite flotation
Autorzy:
Xu, Wenlu
Sun, Kangkang
Qiu, Yangshuai
Zhang, Lingyan
Yang, Luo
Wei, Shaowei
Ding, Dafa
Powiązania:
https://bibliotekanauki.pl/articles/2146848.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flake graphite
mica
quartz
flotation
entrainment
Opis:
Flotation is one of the most common and effective methods for the beneficiation of natural graphite resources. However, the upgrading efficiency of flotation is always finite due to the undesirable collection of gangue minerals. In this work, the collecting mechanism of three typical gangue minerals, including mica, quartz, and feldspar, in fine flake graphite flotation was investigated. Results of batch flotation tests for single-minerals and artificial mixtures confirmed the enhanced collection of gangues in the presence of graphite particles. Contact angle and zeta potential results and theoretical calculations of the interaction between graphite and gangue particles based on typical DLVO theory indicated that it is impossible to collect gangue minerals by true flotation or through heterocoagulation with graphite particles. The fitting results of accumulated gangue recoveries and accumulated water recoveries using the Warren method demonstrated that most gangue minerals entered the concentrate through entrainment, with a small proportion by bubble inclusions.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 1; 101--112
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Manganese on the Crystallisation Process, Microstructure and Selected Properties of Compacted Graphite iron
Autorzy:
Gumienny, G.
Kurowska, B.
Just, P.
Powiązania:
https://bibliotekanauki.pl/articles/354354.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
compacted graphite iron
crystallization
manganese
DTA method
Opis:
The paper presents the effect of manganese on the crystallization process, microstructure and selected properties: cast iron hardness as well as ferrite and pearlite microhardness. The compacted graphite was obtained by Inmold technology. The lack of significant effect on the temperature of the eutectic transformation was demonstrated. On the other hand, a significant reduction in the eutectoid transformation temperature with increasing manganese concentration has been shown. The effect of manganese on microstructure of cast iron with compacted graphite considering casting wall thickness was investigated and described. The nomograms describing the microstructure of compacted graphite iron versus manganese concentration were developed. The effect of manganese on the hardness of cast iron and microhardness of ferrite and pearlite were given.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1269-1275
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of colloidal montmorillonite particles on froth flotation of graphite, galena and fluorite
Autorzy:
Chen, T.
Zhao, Y.
Li, H.
Song, S.
Powiązania:
https://bibliotekanauki.pl/articles/110589.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
montmorillonite
graphite
galena
fluorite
slime coating
entrainment
Opis:
The effect of colloidal montmorillonite (MMT) on froth flotation of graphite, galena and fluorite was investigated in this work. The results showed that the presence of sufficient amount of colloidal MMT particles in the mineral slurry would be detrimental of flotation by reducing the recovery of minerals. This observation was attributed to slime coating of MMT on the coarse valuable mineral particles and entrainment of MMT particles in the froth product together with water in the triangle froth zones. The former would reduce the recovery of the valuable minerals because of hydrophilic MMT coating. The latter would decrease the concentrate grade. The degree of slime coating depended on slurry pH, while the degree of entrainment was closely related to water recovery. It was also found that slime coating was a dominant factor in mineral flotation in acidic pH regions in the presence of colloidal MMT particles.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 699-713
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Graphite in an archaeological context comparing to other black substances – research problems and prospects
Autorzy:
Trąbska, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/2085848.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Rzeszowski. Instytut Archeologii Uniwersytetu Rzeszowskiego. Muzeum Okręgowe w Rzeszowie
Tematy:
black substances
black layers
graphite
archaeology
fingerprints
Opis:
In the archaeological context, substances with a black color have been extensively used in many ancient communities, in the form of items and layers, with the use of biogenic and mineral substances, and requiring a separate methodological approach. Each of them behaves differently in technological and postdepositional processes. The potential degree of the complexity of intentionally applied layers (e.g. paints or cosmetics) and the overlap of secondary substances and crusts, increases difficulties in obtaining unambiguous results and their interpretation. Graphite plays an important role among them. Several areas of the current use of graphite are, or at least could be, commonly shared in the present and in the past, and thus their analysis could be inspiring for archaeology and archaeometry. Graphite fingerprint and potential fingerprints are discussed in terms of their variability. The problem of graphitization as a potential source of misleading interpretation is discussed.
Źródło:
Analecta Archaeologica Ressoviensia; 2020, 15; 17-29
2084-4409
Pojawia się w:
Analecta Archaeologica Ressoviensia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie spektroskopii Ramana w badaniu minerałów pozaziemskich wybranych meteorytów
Raman spectroscopy investigations of extraterrestrial minerals of certain meteorites
Autorzy:
Szurgot, Marian
Kozanecki, Marcin
Karczemska, Anna
Mitura, Stanisław
Powiązania:
https://bibliotekanauki.pl/articles/1032698.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
Canyon Diablo
Confocal Raman micro-spectroscopy
DaG 610
NWA 869
diamond
extraterrestrial matter
graphite
graphite nodule
lonsdaleite
Opis:
Ordinary chondrites DaG 610 and NWA 869, as well as graphite nodules from Canyon Diablo iron meteorites were investigated by confocal Raman microspectroscopy in order to identify extraterrestrial minerals. Olivines, orthopyroxenes (enstatite, bronzite and hyperstene), clinopyroxenes (pigeonite), plagioclase, troilite and various carbon phases, mainly graphite and diamond have been identified and characterized.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2009, 1; 156-160
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of process of removing impurities from calcium carbonate
Autorzy:
Hann, D.
Kortnik, J.
Powiązania:
https://bibliotekanauki.pl/articles/110465.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
calcium carbonate
flotation of graphite
ISO brightness
Opis:
Calcium carbonate is used as an additive in the production of paper and some other production processes. The aim of this study was to determine the chances of the calcite sample to be mechanically cleaned of impurities, so that the material can become commercially interesting, primarily to be sold to the paper and other-related industries. A mineralogical petrographic investigation carried out on a sample of calcite showed that an unfavorable impurity is, in particular, graphite – which is otherwise fairly easily to remove by flotation. Flotation was performed with samples of different particle size. The purpose of this was to find an optimal particle size for carrying out the flotation. In order to achieve an effective flotation results it is first necessary to achieve a proper liberation of grains. The second part of the study was to explore the optimal sequence of treatment procedures for tested calcite, using milling, flotation, and sedimentation.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 2; 611-619
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nickel in Compacted Graphite Iron
Autorzy:
Gumienny, G.
Kurowska, B.
Szymczak, T.
Gawroński, J.
Powiązania:
https://bibliotekanauki.pl/articles/352803.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
compacted graphite iron
crystallization process
DTA method
Opis:
The paper presents results of the research work concerning effects of nickel concentration on the crystallization process, microstructure and selected properties of the compacted graphite iron. Compacted graphite in the cast iron was obtained with use of the Inmold process. The study has comprised the cast iron containing nickel up to concentration providing obtainment of austenitic microstructure of the matrix. The effect of the nickel on temperature of the eutectic crystallization was specified. It has been presented composition of the cast iron matrix in function of nickel concentration in a casting with wall thickness of 3 mm and 24 mm. Moreover, it has been presented conditions defining the possibility of obtaining an austenitic and martensitic compacted graphite iron. Effect of the nickel on hardness of the cast iron was described.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 657-662
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Właściwości przetwórcze kompozytów polipropylenowych modyfikowanych grafitem ekspandowanym
Processing properties of polypropylene composites modified expanded graphite
Autorzy:
Tartakowski, Z.
Lewandowska-Kosyl, J.
Kosyl, M.
Powiązania:
https://bibliotekanauki.pl/articles/278237.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Inżynierii Materiałów Polimerowych i Barwników
Tematy:
grafit ekspandowany
polipropylen
kompozyt
expanded graphite
polypropylene
composite
Opis:
W artykule przedstawiono wyniki badań właściwości przetwórczych kompozytów polipropylenowych modyfikowanych grafitem ekspandowanym (PP/EGexp), do zastosowań na wyroby techniczne. Udział napełniacza grafitowego w kompozytach wynosił 1, 2,5 i 5% wag. Analizowano wpływ wielkości cząstek i ich udział wagowy na właściwości przetwórcze wytworzonych kompozytów. Badano stopień wypełnienia gniazda formującego o kształcie spiralnym i wielostopniowym, skurcz wtryskowy przy różnych parametrach przetwórczych (ciśnienie wtryskiwania, temperatura wtryskiwania) oraz masowy wskaźnik szybkości płynięcia materiałów kompozytowych. Stwierdzono, że ilość i wielkość cząstek grafitowych wpływa na zmniejszenie skurczu wtryskowego. Wzrost temperatury przetwórstwa i ciśnienia wtryskiwania, powoduje zwiększenie wypełnienia gniazda formującego. Wykazano również, że poprzez zmianę parametrów przetwórstwa można regulować stopień wypełnienia gniazda formującego. Przeprowadzone badania potwierdziły, możliwość aplikacji materiałów na specjalne wyroby techniczne o złożonej geometrii kształtu.
This paper presents the results of processing properties of polypropylene composites modified expanded graphite (PP / EGexp), which may be used for technical products for special application. The share of graphite filler in composites were 1, 2.5 and 5 wt%. The influence of particle size and the weight fraction on the processing properties of the composites produced has been studied. Materials were tested degree of filling of the cavity in a spiral shape, shrinkage after injection. Also analyzed the degree of filling the mold with the socket in the stepped shape of the product at different processing parameters (injection pressure, injection temperature) and the melt flow rate of composite materials. It was found that the amount and size of graphite particles reduces shrinkage after injection. The increase in processing temperature and injection pressure, increases the filling cavity. It was also shown that by varying the processing parameters can be adjusted by the degree of filling the cavity. The study confirmed the possibility of the application materials for special technical products with complex geometry shape.
Źródło:
Przetwórstwo Tworzyw; 2014, [R.] 20, nr 4 (160), 4 (160); 344-348
1429-0472
Pojawia się w:
Przetwórstwo Tworzyw
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Artificial Intelligence Approaches to Determine Graphite Nodularity in Ductile Iron
Autorzy:
Brait, Maximilian
Koppensteiner, Eduard
Schindelbacher, Gerhard
Li, Jiehua
Schumacher, Peter
Powiązania:
https://bibliotekanauki.pl/articles/2056034.pdf
Data publikacji:
2021
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
ductile iron
graphite nodularity
graphite morphology
artificial intelligence
machine learning
żeliwo sferoidalne
guzkowatość grafitu
morfologia grafitu
sztuczna inteligencja
uczenie maszynowe
Opis:
The complex metallurgical interrelationships in the production of ductile cast iron can lead to enormous differences in graphite formation and local microstructure by small variations during production. Artificial intelligence algorithms were used to describe graphite formation, which is influenced by a variety of metallurgical parameters. Moreover, complex physical relationships in the formation of graphite morphology are also controlled by boundary conditions of processing, the effect of which can hardly be assessed in everyday foundry operations. The influence of relevant input parameters can be predetermined using artificial intelligence based on conditions and patterns that occur simultaneously. By predicting the local graphite formation, measures to stabilise production were defined and thereby the accuracy of structure simulations improved. In course of this work, the most important dominating variables, from initial charging to final casting, were compiled and analysed with the help of statistical regression methods to predict the nodularity of graphite spheres. We compared the accuracy of the prediction by using Linear Regression, Gaussian Process Regression, Regression Trees, Boosted Trees, Support Vector Machines, Shallow Neural Networks and Deep Neural Networks. As input parameters we used 45 characteristics of the production process consisting of the basic information including the composition of the charge, the overheating time, the type of melting vessel, the type of the inoculant, the fading, and the solidification time. Additionally, the data of several thermal analysis, oxygen activity measurements and the final chemical analysis were included. Initial programme designs using machine learning algorithms based on neural networks achieved encouraging results. To improve the degree of accuracy, this algorithm was subsequently adapted and refined for the nodularity of graphite.
Źródło:
Journal of Casting & Materials Engineering; 2021, 5, 4; 94--102
2543-9901
Pojawia się w:
Journal of Casting & Materials Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aparaturowe i metodologiczne aspekty ilościowej analizy mikrostruktury żeliwa
Quantitative analysis of cast iron microstructure in terms of the apparatus and methodology
Autorzy:
Warmuzek, M.
Boroń, Ł.
Tchórz, A.
Powiązania:
https://bibliotekanauki.pl/articles/391395.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa
Tematy:
mikrostruktura
analiza obrazu
grafit
żeliwo
parametry stereologiczne
klasyfikacja grafitu
microstructure
image analysis
graphite
cast iron
stereological parameters
graphite classification
Opis:
W pracy porównano wyniki zastosowania różnych systemów obrazowania mikrostruktury (mikroskop świetlny oraz tomograf rentgenowski) oraz różnych systemów analizy obrazu do pomiaru wybranych parametrów stereologicznych i geometrycznych dla dwóch modeli morfologicznych, występujących w stopach odlewniczych, na przykładzie żeliwa z grafitem sferoidalnym i kratkowym. Wykazano statystycznie istotne różnice pomiędzy uzyskanymi wynikami pomiarów, spowodowane przede wszystkim jakością obrazu poddanego analizie oraz lokalnymi cechami geometrycznymi analizowanych obiektów. Porównano wyniki klasyfikacji wydzieleń grafitu według klas wielkości przyjętych w obowiązującej normie PN-EN ISO 945-1, przeprowadzonej na podstawie różnych procedur obrazowania.
In this work the results of the application of different imaging techniques and image analysis systems for measurements of chosen either stereological parameters or geometrical features for some of morphology models occurring in the cast alloys, especially taking into account cast iron with either spheroidal or vermicular graphite have been compared and interpreted. The statistical important difference of the obtained results have been stated and recognized as caused first of all by quality of analyzed images and local geometry features of the analyzed objects. The results of the graphite particles classification according to the size class in the actual standard PN-EN ISO 945-1, using different imaging and analysis procedures.
Źródło:
Prace Instytutu Odlewnictwa; 2011, 51, 3; 59-87
1899-2439
Pojawia się w:
Prace Instytutu Odlewnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ dodatku grafitu na strukturę i właściwości spiekanych biomateriałów kompozytowych na bazie tytanu
The influence of sintering temperature on the structure and properties of titanium-graphite composites
Autorzy:
Deptuła, P.
Dąbrowski, J. R.
Powiązania:
https://bibliotekanauki.pl/articles/285155.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
biomateriały kompozytowe
grafit
tytan
composite biomaterials
graphite
titanium
Źródło:
Engineering of Biomaterials; 2009, 12, no. 89-91; 140-142
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of mechanical flotation cell and cyclonic microbubble flotation column in terms of separation performance for fine graphite
Autorzy:
Bu, X.
Zhang, T.
Chen, Y.
Peng, Y.
Xie, G.
Wu, E.
Powiązania:
https://bibliotekanauki.pl/articles/110791.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
mechanical flotation
column flotation
Fuerstenau upgrading curve
graphite
Opis:
Comparison of flotation performance between the flotation column and mechanical flotation was carried out to promote the grade and economic value of the graphite ore (15.40% ash content). The ash content of the concentrate of the mechanical flotation was 10.77% at the yield of 79.34%. In contrast, the yield of the concentrate of the column flotation was increased to 88.93% with 10.55% ash content. Comparative study of the Fuerstenau upgrading curves indicated that the column flotation was more efficient for cleaning the graphite ore in the presence of the centrifugal force field, nanobubbles (generated by hydrodynamic cavitation), and the thicker froth layer in comparison with the mechanical flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 732-740
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of expanded graphite (EG) and graphene oxide (GO) on physical properties of PET based nanocomposites
Autorzy:
Paszkiewicz, S.
Nachman, M.
Szymczyk, A.
Špitalský, Z.
Mosnáček, J.
Rosłaniec, Z.
Powiązania:
https://bibliotekanauki.pl/articles/778760.pdf
Data publikacji:
2014
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
in situ polymerization
PET
graphene oxide
expanded graphite
Opis:
This work is the continuation and refinement of already published communications based on PET/EG nanocomposites prepared by in situ polymerization1, 2. In this study, nanocomposites based on poly(ethylene terephthalate) with expanded graphite were compared to those with functionalized graphite sheets (GO). The results suggest that the degree of dispersion of nanoparticles in the PET matrix has important effect on the structure and physical properties of the nanocomposites. The existence of graphene sheets nanoparticles enhances the crystallization rate of PET. It has been confirmed that in situ polymerization is the effective method for preparation nanocomposites which can avoid the agglomeration of nanoparticles in polymer matrices and improve the interfacial interaction between nanofiller and polymer matrix. The obtained results have shown also that due to the presence of functional groups on GO surface the interactions with PET matrix can be stronger than in the case of exfoliated graphene (EG) and matrix.
Źródło:
Polish Journal of Chemical Technology; 2014, 16, 4; 45-50
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wear Mechanism of Spheroidal Cast Iron Piston Ring-Aluminum Matrix Composite Cylinder Liner Contact
Autorzy:
Bąkowski, H.
Powiązania:
https://bibliotekanauki.pl/articles/352888.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cast iron
spheroidal graphite
wear mechanism
stereological parameters
Opis:
The paper presents the results of research on the impact of stereological characteristics of microstructure of graphite in nodular GJS-400 cast iron and Al2 O3 fibers in the composite AC-47000 + 10% Al2 O3 F on the mechanism of wear in a cast iron piston ring – composite cylinder liner contact in a combustion engine. To elucidate the mechanisms of wear in the tested contact was used Finite Element Method (FEM). On the basis of quantitative metallographic examination of test materials were determined stereological parameters of their structures. It was necessary for the implementation of the 3D model that reflects the actual structure with particular focus on the different phases in order to determine the distribution of stresses and strains. The determination Strains of the local stresses value of allowed the prediction of wear initiating places. Formation of stereological parameters of cast iron in the technological process allows a prediction of values and distributions of the stresses/strains and thus reduce wear and extend durability of the analyzed contact.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 481-490
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on Electromagnetic Properties of Graphite/Graphene/Silver-Coated Copper Powder Monolayer Coated Composites
Autorzy:
Liu, Yuanjun
Han, Xiaohui
Bao, Wenli
Ding, Xiongwei
Zhao, Xiaoming
Powiązania:
https://bibliotekanauki.pl/articles/24200927.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
graphite
graphene
copper powder
coated composite
electromagnetic properties
Opis:
With the rapid development of electronic technology and military techniques, electromagnetic protection materials are becoming more and more significant to people. Harmful electromagnetic radiation not only affects the normal operation of electronic equipments and military security, but also has a serious impact on human health. At present, using absorbing and shielding materials are effective means to reduce the harm of electromagnetic waves. In this project, graphite, graphene and silver-coated copper powder coated composites were prepared using PU-2540 polyurethane and adopting a coating process for the substrate on plain polyester/cotton fabric. The controlled variable method was used to prepare and study the electromagnetic properties of single-layer coating composites with different functional particle contents. The result showed that within the frequency range of 0.01GHz~1.0GHz, when the total mass of functional particles was 48% relative to that of the polyurethane, the value of the real part of the dielectric constant of the sample remained the largest and its polarization ability was the strongest. Within the frequency range of 0.08GHz~1.0GHz, when the content of functional particles was 24% relative to that of the polyurethane, the value of the imaginary part of the dielectric constant and the loss of the tangent value of the sample kept the maximum, and the loss and attenuation ability with respect to electromagnetic waves were both the strongest. Within the frequency range of 1.3GHz~2.0GHz, when the content of functional particles was 36% relative to that of the polyurethane, the value of the reflection loss of the sample was -26.93dB, and the minimum value of the reflection loss was obtained at a frequency of 1.6GHz, at the moment of which, the absorbing property of the sample was the best.
Źródło:
Fibres & Textiles in Eastern Europe; 2023, 31, 1; 83--90
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Reliability of the Results of the Modified Low-cycle Fatigue Test for Cast Iron Evaluated by Metallographic Studies
Autorzy:
Maj, M.
Pietrzak, K.
Powiązania:
https://bibliotekanauki.pl/articles/379799.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cast iron
lamellar graphite
spheroidal graphite
low cycle fatigue test
mechanical properties
żeliwo
grafit płatkowy
grafit sferoidalny
zmęczenie niskocyklowe
właściwości mechaniczne
Opis:
This study discloses the characteristic features of the modified low-cycle fatigue test used for the determination of the mechanical properties of two types of cast iron, i.e. EN-GJL-250 and EN-GJS-600-3. For selected materials, metallographic studies were also conducted in the range of light microscopy and scanning microscopy.
Źródło:
Archives of Foundry Engineering; 2015, 15, 1; 41-46
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reducing entrainment of sericite in fine flaky graphite flotation using polyaluminum chloride
Autorzy:
Qiu, Yangshuai
Zhang, Lingyan
Sun, Kangkang
Li, Ye
Qian, Yupeng
Powiązania:
https://bibliotekanauki.pl/articles/109740.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fine flaky graphite
sericite
polyaluminum chloride (PACl)
dispersion
aggregation
Opis:
Polyaluminum chloride (PACl) was introduced as a flocculant to reduce the entrainment of sericite gangue in fine flaky graphite flotation. The dispersion and aggregation behaviours of sericite and fine flaky graphite in the absence and presence of PACl were studied by settling experiments and verified by optical microscope images. Results of batch flotation tests for artificial mixtures indicated that the addition of PACl decreased the recovery of sericite gangue and the water recovery. Zeta potential measurements, FTIR and XPS analyses revealed that PACl selectively aggregated sericite particles in terms of charge neutralization and precipitate enmeshment.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 5; 1108-1119
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of Microstructure of Grey Cast Irons by Electrical Resistivity Measurements
Autorzy:
Petrič, M.
Mrvar, P.
Kastelic, S.
Powiązania:
https://bibliotekanauki.pl/articles/354044.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
solidification
grey cast iron
electrical resistivity
graphite shape
microstructure
Opis:
The paper describes the influence of graphite shape, size and amount to electrical properties of different cast irons. Experiments of electrical resistivity measurements were conducted during solidification of four different melts in different time intervals from melt treatment by inoculation and nodularization. Metallographic analyses were made in order to determine the shape, size, distribution and amount of graphite and correlate results with electrical resistivity measurements. It was found out that nodular graphite is giving the lowest electrical resistivity and is decreased during solidification. Electrical resistivity of lamellar cast iron is increased during solidification since lamellas interrupt metal matrix severely. There is no significant difference in resistivity of vermicular cast iron from nodular cast iron. Smaller size of graphite and lower amount of graphite and higher amount of metal matrix also decrease resistivity.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 1; 365-369
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selected the Casting Properties of the Composites AlMg10+Cgr
Autorzy:
Łągiewka, M.
Powiązania:
https://bibliotekanauki.pl/articles/355986.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aluminium alloys
metal composites
graphite particles
castability
surface tension
Opis:
The paper is a review of the previous investigations concerning the influence of graphite particles both on the casting properties of metal matrix composites (MMCs). The work presents the examination results of casting properties (i.e. castability and shrinkage) of the MMCs with matrices of a selected aluminium alloy reinforced with graphite particles. There is also presented the influence of graphite particles on the surface tension and viscosity of the flowing and filling the mould composite suspension. The suspensions containing various percentages of graphite particles (namely 5%, 10%, or 15% in volume) were prepared in order to perform the above mentioned examinations. Castability (fluidity) of these suspensions was measured in two ways, i.e. by means of both the spiral test and the rod test, while their shrinkage was determined with the use of a device designed and assembled in the Department of Foundry Engineering, CUT. The device enables to determine changes in the length of a casting during its solidification with respect to the specified length of the test rod. The surface tension was determined by the wedge casting method consisting in the pouring of metal into an open shell mould with the cavity of wedge geometry, the sharp edge being perpendicular to the free metal surface. The change in viscosity corresponding to the change in graphite particles percentage was calculated from Einstein’s equation. The results of examinations show that the introduction of reinforcing graphite particles results in both a significant increase in the viscosity of the flowing suspension and a considerable decrease in its castability. The greater dimensional stability of castings was observed, i.e. the shrinkage of composite castings was smaller than the shrinkage of matrix alloy itself. An increase in surface tension index value with an increase in volume percentage of graphite particles in composite was also noticed.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 3; 1585-1589
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Odporność ogniowa kompozytów EVA modyfikowanych grafitem ekspandującym
Fire resistance of EVA composites modified with expanding graphite
Autorzy:
Tartakowski, Z.
Kosyl, M.
Lewandowska-Kosyl, J.
Powiązania:
https://bibliotekanauki.pl/articles/278006.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Inżynierii Materiałów Polimerowych i Barwników
Tematy:
grafit ekspandujący
kompozyt
palność
EVA
expanding graphite
composite
flame retardant
Opis:
W niniejszej pracy przedstawiono badania kompozytów polimerowych o zmniejszonej palności z zastosowaniem bezhalogenowych środków ograniczających palność. Przedmiotem badań były kompozyty na osnowie kopolimeru etylen(octan-winylu) modyfikowane uniepalniaczem w postaci grafitu ekspandującego. Badano wpływ ilości (10, 20 i 30% wag.) oraz wielkości cząstek napełniacza (cząstki do 41 μm oraz 200÷300 μm) na odporność ogniową kompozytów metodą UL94HB, temperaturę mięknienia wg Vicata i stopnień ekspandowania. Próba poziomego palenia wykazała, że wszystkie kompozyty należą do klasy szybkości palenia HB a wraz ze wzrostem zawartości grafitu ekspandującego, maleje czas palenia się próbek. Z badań wynika, że wraz ze wzrostem ilości napełniacza wzrasta temperatura mięknienia wg Vicata oraz zwiększeniu ulega stopień wyekspandowania badanych materiałów.
In this paper presents the polymer composites with reduced flammability without using halogen flame retardant restrictive measures. Composites were studied on the base of ethylene (ethyl-vinyl) modified uninflaming agent in the form of expanding graphite. The research was the influence of the amount (10-30%) and particle size (particle to 41 μm and 200 to 300 microns) on the fire resistance test method UL94HB. In addition, the materials produced were tested Vicat softening temperature, and study the degree of expansion. Attempting horizontal burning showed that all belong to the class of composites burning rate HB and with the expanding graphite content increases, decreasing the burning time of the samples. Research shows that with increasing amount of filler increases Vicat softening temperature as well as to increase the degree of ekspanding of tested materials.
Źródło:
Przetwórstwo Tworzyw; 2014, [R.] 20, nr 4 (160), 4 (160); 340-343
1429-0472
Pojawia się w:
Przetwórstwo Tworzyw
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cast Hybrid Composites Designated for Air Compressor Pistons
Autorzy:
Dolata, A. J.
Dyzia, M.
Jaworska, L.
Putyra, P.
Powiązania:
https://bibliotekanauki.pl/articles/356742.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hybrid aluminium composites
glassy carbon
graphite particles
mould casting
machining
Opis:
The main purpose of the investigations was to develop the phase composition of the composite assuming that the component selection criterion will be the formability of piston work surfaces during the machining. Wear resistance under the friction conditions was assumed as the additional parameter for the assessment of composite material. In the study were used AlSi7Mg/SiC+Cg and AlSi7Mg/SiC+GR hybrid composites prepared by the stir casting method.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2A; 705-708
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of Chunky Graphite in Nodular Cast Iron on the Base of Numerical Simulation and Experimental Data
Autorzy:
Bauer, B.
Mihalic Pokopec, I.
Petrič, M.
Mrvar, P.
Powiązania:
https://bibliotekanauki.pl/articles/352270.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
chunky graphite
nodular cast iron
numerical simulation
cooling curve
microstructure
Opis:
Chunky graphite has been recognized for a long time as one of the major problems in production of heavy section nodular cast iron. A great number of studies have been conducted to describe the chunky graphite formation, but a clear understanding of its appearance and a safe mastering of the melt preparation to avoid chunky graphite are not yet available. In the present work the cooling curves were recorded in large cone blocks and standard TA cup. According to measured data from the cone block, melt characteristics and heat transfer coefficient between casting and mould were adjusted in the ProCAST® simulation software. For a near-eutectic nodular cast iron test melt with 0.7 wt.% Ni, relationship between the area of the cone block affected by chunky graphite and simulation software results has been observed, i.e., thermal modulus and time to solidus.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 1; 343-347
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porous Composite for Bipolar Plate in Low Emission Hydrogen Fuel Cells
Autorzy:
Wlodarczyk, R.
Powiązania:
https://bibliotekanauki.pl/articles/124824.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
fuel cells
bipolar plates
graphite composites
structural analysis
corrosion resistance
Opis:
The paper presents the results of graphite-stainless steel composites for the bipolar plates in low-temperature fuel cells. The sinters were performed by powder metallurgy technology. The influence of technological parameters, especially molding pressure were examined. Following the requirements formulated by the DOE concerning the parameters of the materials, it indicated by the value of the parameters. The density, flowability, particle size of graphite and stainless steel powders have been evaluated. Composites have been tested by microstructure and phase analysis, properties of strength, functional properties: wettability, porosity, roughness. The special attention was paid to the analysis of corrosion resistance obtained sinters and influence of technological parameters on the corrosion. Corrosion tests were carried out under conditions simulating the environment of the fuel cell under anode and cathode conditions. The effect of pH solution during working of the cell on corrosion resistance of composites have been evaluated. Contact resistance depends on roughness of sinters. Low ICR determined high contact area GDL-BP and high electrical conductivity on the contact surface. The ICR in anode conditions after corrosion tests are not change significantly; composite materials can be used for materials for BP in terms of H2.
Źródło:
Journal of Ecological Engineering; 2018, 19, 1; 225-232
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Production and characterization of polyurethane/expanded graphite composites for industrial food preservation
Otrzymywanie i charakterystyka kompozytów poliuretan/grafit ekspandowany do konserwacji żywności metodą przemysłową
Autorzy:
Güngör Ertuğral, Tuğba
Powiązania:
https://bibliotekanauki.pl/articles/2202592.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
polyurethane
expanded graphite
composites
insulation
poliuretan
grafit ekspandowany
kompozyty
izolacja
Opis:
Thermal insulation materials extend the shelf life of food and reduce energy consumption. Polyurethane (PU) insulation materials are often used to keep food hot and cold. Improving the thermal insulation properties of PU can significantly contribute to energy savings and lower food-related costs in the food and pharmaceutical industries. Polyurethane/expanded graphite (PU/EG) composites were obtained by hot-pressing by adding expanded graphite (EG) to PU foams. Composites with 0.05%, 5%, and 10% EG were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and thermogravimetric analysis (TGA).
Materiały termoizolacyjne wydłużają okres przydatności do spożycia żywności oraz zmniejszają zużycie energii. Poliuretanowe (PU) materiały izolacyjne są często stosowane do przechowywania żywności na gorąco i na zimno. Poprawa właściwości termoizolacyjnych PU może znacząco przyczynić się do oszczędności energii i obniżenia kosztów związanych z żywnością w przemyśle spożywczym i farmaceutycznym. Kompozyty poliuretan/ekspandowany grafit (PU/EG) wytworzono metodą prasowania na gorąco poprzez dodanie ekspandowanego grafitu (EG) do pianek PU. Kompozyty z udziałem 0,05% mas., 5% mas. i 10% mas. EG scharakteryzowano za pomocą spektroskopii w podczerwieni z transformacją Fouriera (FTIR), skaningowego mikroskopu elektronowego (SEM) i analizy termograwimetrycznej (TGA).
Źródło:
Polimery; 2022, 67, 11-12; 588--594
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of expanded graphite coming from the electrochemical oxidation of phenol on cement-polymer matrix
Autorzy:
Ślosarczyk, A.
Krawczyk, P.
Powiązania:
https://bibliotekanauki.pl/articles/778970.pdf
Data publikacji:
2016
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
cement-polymer matrix
expanded graphite
surface treatment
adhesion
mechanical properties
Opis:
In presented article the polymer-modified cement mortars with expanded graphite covered by the oligomer film, being a by-product of phenol electro-oxidation, were investigated. The changes in the morphology of EG and EG/oligomer as well as in the microstructure of cement-polymer composites modified with EG/oligomer were verified using the scanning electron microscopy (SEM). The evaluation of adhesion between EG/oligomer and cement-polymer mortar based on the mechanical tests, especially their flexural behavior. It was shown that the oligomer film formed on EG surface made graphite flakes more durable and resistant to bending. Moreover, the oligomer due to the interaction with polymer network in cement-polymer mortar led to the improvement of flexural toughness of composite.
Źródło:
Polish Journal of Chemical Technology; 2016, 18, 4; 5-8
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antistatic polyethylene free-standing films modified with expanded graphite – technological aspects
Antystatyczne foliepolietylenowe modyfikowane grafitem ekspandowanym – aspekty technologiczne
Autorzy:
Imiołek, Paweł
Kasprowicz, Krzysztof
Laska, Jadwiga
Powiązania:
https://bibliotekanauki.pl/articles/947110.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
polyethylene
expanded graphite
antistatic films
polietylen
grafit ekspandowany
folie antystatyczne
Opis:
The main goal of this research was to develop antistatic polyethylene films with a surface resistance of ≤109 Ω. The research involved testing low density polyethylene/linear low density polyethylene (PE-LD/PELLD) filled with various amounts of expanded graphite EG 096. The samples were made by hot pressing and injection molding. Mechanical and electrical properties were tested. The research results show that samples with a content of 30% by weight of expanded graphite are characterized by good mechanical properties, e.g. Young’s modulus of the filled PE was higher by 195% compared to pure polyethylene.
Głównym celem prezentowanych badań było opracowanie antystatycznych folii polietylenowych o oporności powierzchniowej ≤109 Ω. W pracy zbadano polietylen małej gęstości (PE-LD/PE-LLD) napełniony różną ilością grafitu ekspandowanego EG 096. Próbki wykonano metodą prasowania na gorąco i formowania wtryskowego. Zbadano ich właściwości mechaniczne oraz elektryczne. Na podstawie wyników badań stwierdzono, że próbki o zawartości 30% mas. grafitu ekspandowanego charakteryzują się korzystnymi właściwościami mechanicznymi, np. moduł Younga napełnionego PE był o 195% większy niż polietylenu bez udziału napełniacza.
Źródło:
Polimery; 2020, 65, 4; 275-279
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-temperature carbothermal dephosphorization of Malaysian monazite
Autorzy:
Udayakumar, Sanjith
Sheikh Abdul Hamid, Sheikh Abdul Rezan
Baharun, Norlia
Pownceby, Mark
Powiązania:
https://bibliotekanauki.pl/articles/2146886.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
malaysian monazite concentrate
dephosphorization
carbothermal reduction
rare earth elements
graphite
Opis:
High-temperature carbothermal reduction experiments with graphite powder were conducted to assess the dephosphorization behavior of Malaysian monazite concentrate. Thermodynamic analysis of the possible dephosphorization reactions was conducted to evaluate the feasibility of the carbothermal reduction of the monazite phases. The effects of temperature, particle size, and monazite to carbon ratio were then investigated under different conditions. The carbothermal reduction experiments were conducted based on the Taguchi design method, and up to 97% of phosphorous removal was achieved under optimized conditions. The optimal conditions for dephosphorization were determined as; a reduction temperature of 1350 °C, a particle size of -75 μm, and monazite to carbon molar ratio of 0.3. Microstructural and phase characterization of the dephosphorized products revealed that CeO2, Nd2O3, La2O3, and Pr2O3 oxide phases were prominent, and no residual peaks of monazite remained in the reduced products. The information gained from the study can aid in the design of a suitable post-dephosphorization hydrometallurgical treatment for exploiting Malaysian monazite as a local source of REEs.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 6; 140--155
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Minerały akcesoryczne w meteorycie Morasko
Acessory minerals of meteorite Morasko
Autorzy:
Grzegolec, Urszula
Muszyński, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1032974.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
Morasko meteorite
graphite nodules
meteorites
meteoryt Morasko
nodule troilitowo-grafitowe
troilite
Źródło:
Acta Societatis Metheoriticae Polonorum; 2013, 4; 132-133
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polish scientists in studies of extraterrestrial matter; past, present, reminiscences
Autorzy:
Manecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/2059311.pdf
Data publikacji:
2001
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
meteorites
structures of chondrules
chondrules
cosmic dusts
cosmic glass
cosmic graphite
Opis:
The contributions of Polish scientists to studies of extraterrestrial matter are described, and a history of investigations into the Pułtusk, Łowicz, Morasko and Baszkówka meteorites is given. Opinions expressed in Polish journals on the structure and genesis of chondrules are discussed, together with the results of X-ray structural research of graphites. Polish papers devoted to the studies of cosmic dusts, particularly of their aluminosilicate glass, are summarized. In this context the use of the infrared method in distinguishing terrestrial and cosmic glasses is stressed.
Źródło:
Geological Quarterly; 2001, 45, 3; 211-218
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie nowatorskiej metody pomiaru aktywności tlenu w kontroli procesu wytwarzania żeliwa sferoidalnego
A novel method for the oxygen activity measurment applied in control of the ductile iron manufacturing process
Autorzy:
Kuder, M.
Powiązania:
https://bibliotekanauki.pl/articles/391494.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa
Tematy:
żeliwo
grafit
tlen
aktywność
Celox®-Foundry
cast iron
graphite
oxygen
activity
Opis:
Celem pracy była ocena metody pomiaru aktywności tlenu w ciekłym żeliwie dla prognozowania właściwości żeliwa po zakrzepnięciu. Przeprowadzono szereg wytopów doświadczalnych, wykonując pomiary aktywności tlenu po roztopieniu wsadu, obróbce stopami magnezu w zróżnicowanej ilości oraz podczas długotrwałego przetrzymywania stopu w tyglu pieca. Określono podstawowy skład chemiczny żeliwa, postać grafitu, a w wybranych przypadkach całkowitą zawartość gazów (O, N, H) oraz wytrzymałość i wydłużenie. Stwierdzono wpływ aktywności tlenu na morfologię grafitu i po spełnieniu określonych warunków techniczno-organizacyjnych, użyteczność tej metody do kontroli i sterowania procesem wytwarzania żeliwa sferoidalnego.
The objective of the present study was to evaluate a method for the measurement of oxygen activity in liquid cast iron to predict the cast iron properties after solidification. A series of experimental melts were made, testing the activity of oxygen after melting down of the charge, treatment with varying amounts of magnesium alloys, and during prolonged holding of the melt in a crucible furnace. The basic chemical composition of cast iron, the graphite form, and in some cases, the total gas content (O, N, H) as well as the strength and elongation were determined. The influence of oxygen activity on the morphology of graphite was stated and, provided certain technical and organisational conditions are met, the usefulness of this method in control of the ductile iron manufacturing process was confirmed.
Źródło:
Prace Instytutu Odlewnictwa; 2012, 52, 3; 31-44
1899-2439
Pojawia się w:
Prace Instytutu Odlewnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Shock Resistance of Cast Iron with Various Shapes of Graphite Precipitates
Autorzy:
Jakubus, A.
Soiński, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/379522.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cast iron
graphite precipitates
thermal shock
żeliwo
wydzielenia grafitu
szok termiczny
Opis:
The influence of a shape of graphite precipitates in cast iron on the thermal shock resistance of the alloy was initially determined. Investigations included the nodular cast iron and the vermicular one, as well as the cast iron containing flake graphite. The thermal shock resistance was examined at a special laboratory stand which allowed for multiple heating and cooling of specimens within the presumed temperature range. The specimens were inductively heated and then cooled in water of constant temperature of about 30°C. There were used flat specimens 70 mm long, 5 mm thick in the middle part, and tapering like a wedge over a distance of 15 mm towards both ends. The total length of cracks generated on the test surfaces of the wedge-shaped parts of specimens was measured as a characteristic value inversely proportional to the thermal shock resistance of a material. The specimens heated up to 500°C were subjected to 2000 test cycles of alternate heating and cooling, while the specimens heated up to 600°C underwent 1000 such cycles. It was found that as the heating temperature rose within the 500-600°C range, the thermal shock resistance decreased for all examined types of cast iron. The research study proved that the nodular cast iron exhibited the best thermal shock resistance, the vermicular cast iron got somewhat lower results, while the lowest thermal shock resistance was exhibited by grey cast iron containing flake graphite.
Źródło:
Archives of Foundry Engineering; 2018, 18, 2; 121-124
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Graphite - Polymer - Turbostratic Carbon Composites by Acoustic Emission Method at Perpendicular Geometry
Autorzy:
Berdowska, A.
Berdowski, J.
Aubry, F.
Powiązania:
https://bibliotekanauki.pl/articles/356589.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
compressed expanded graphite
polyfurfuryl alcohol
turbostratic carbon
acoustic emission
composite membrane
Opis:
The purpose of this paper was to search the relations between the structure of the compressed expanded graphite–polymer–turbostratic carbon composites on successive stages of technological treatment and parameters describing the acoustic emission phenomena in these materials. The acoustic emission method can be used for measurements of changes in the structure and many different properties of materials. These investigations are a continuation of our earlier studies concerning physical, mechanical and chemical properties of porous composites created on the basis of a compressed expanded graphite matrix, obtained after successive technological procedures of impregnation, polymerization and carbonization of polyfurfuryl alcohol. The aim of this work was to investigate materials obtained at different levels of technological processing, thus with different densities, porosity, physical and chemical properties, by using the acoustic emission method. In compressed expanded graphite composites structures one can differentiate two basic directions: perpendicular to the bedding plane of graphite flakes and parallel to this one. The all presented results were obtained for the uniaxial strain applied in the direction perpendicular to the bedding plane of the composite structure. Analysis of acoustic emission parameters provides information on physical and chemical processes in these materials.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1287-1293
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of selected trace metals (Cr, Ni, Pb and Cd) in soils by slurry sampling GF AAS
Autorzy:
Cejner, Marzena
Dobrowolski, Ryszard
Reszko-Zygmunt, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/763938.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
Cadmium
Lead
Chromium
Nickel
Slurry sampling graphite furnace atomicabsorption spectrometry
Soil
Opis:
Determination of cadmium, lead, chromium and nickel in soil samples by slurry sampling graphite furnace atomic absorption spectrometry (GFAAS) was presented. Optimization of determination conditions, stability test for slurries and metal partitioning between solid and liquid phase was investigated. The method was successfully tested by the analysis of certified reference materials.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia; 2015, 70, 2
2083-358X
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emisja zanieczyszczeń z procesu grafityzacji elektrod węglowych w piecach LWG (Castnera). Część 2, Wybrane substancje pyłowe
Air pollutant emissions from the graphite process of coal electrodes in the LWG (Castner) Stoves. Part 2, Selected particulate matter substances
Autorzy:
Mazur, M.
Oleniacz, R.
Bogacki, M.
Szczygłowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/269262.pdf
Data publikacji:
2006
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
grafityzacja elektrod węglowych
emisja zanieczyszczeń
graphite process of coal electrodes
pollution
Opis:
W pracy przedstawiono wyniki pomiarów ilości substancji pyłowych odprowadzanych i emitowanych do powietrza z elektrycznych pieców oporowych typu LWG (Castnera) podczas procesu grafityzacji elektrod węglowych. Badaniami objęto pył ogółem, substancje smołowe oraz 16 wielopierścieniowych węglowodorów aromatycznych (WWA). Pomiary przeprowadzono zarówno przed, jak i za systemem oczyszczania gazów odlotowych (dopalanie katalityczne i oczyszczanie mokre). W ten sposób oceniono także zmiany stężeń substancji w gazach pografityzacyjnych po ich przejściu przez system oczyszczania. Jak wynika z przeprowadzonych badań, proces grafityzacji elektrod węglowych w piecu LWG nie jest istotnym źródłem emisji substancji pyłowych, ale w obrębie reaktorów katalitycznego dopalania gazów odlotowych zachodzi zwiększenie zawartości substancji smołowych i WWA w tych gazach oraz zmiana profilu WWA
In the paper the measurement results of quantity of dust pollutants originated and emitted to air from resistor stoves of type LWG (Castner) during graphite process of coal electrodes were introduced. The investigation was carried out for total dust, total tar substances and polycyclic aromatic hydrocarbons (PAHs). The measurements were performed both before and after the flue gas control system (catalytic burning and wet cleaning). Thus changes of the substance concentrations in the gases for the cleaning system were estimated. As a result of the investigation was conclusion that the graphite process of coal electrodes in LWG stoves is not a significant source of dust emissions. Although there is occurred increasing of total tar substances and PAHs concentrations in the gases and changing of PAHs profile within the catalytic reactors using for the flue gas burning
Źródło:
Inżynieria Środowiska / Akademia Górniczo-Hutnicza im. S. Staszica w Krakowie; 2006, 11, 1; 27-38
1426-2908
Pojawia się w:
Inżynieria Środowiska / Akademia Górniczo-Hutnicza im. S. Staszica w Krakowie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polimineralne nodule w gruboziarnistym meteorycie Morasko
Polymineral nodules in coarse-grained Morasko meteorite
Autorzy:
Karwowski, Łukasz
Muszyński, Andrzej
Kryza, Ryszard
Pilski, Andrzej S.
Powiązania:
https://bibliotekanauki.pl/articles/1032667.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
Morasko iron IAB meteorite
altaite
graphite
meteorites
oxides
silicates
sulphides
troilite
Opis:
Morasko meteorite (IAB octahedrite) contains numerous graphite-troilite inclusions. Within these inclusions, many mineral phases have been found, including native elements, sulphides, tellurides, oxides, phosphates and silicates. Apart from dominant graphite and troilite, the following minerals occur: copper, sphalerite, daubreelite, chromite, cosmochlor, enstatite, albite and orthoclase; phosphates (buchwaldite and brianite) are found occasionally, whereas djerfischerite, altaite, olivine and silica are rare. The mineral composition of the nodules suggests a more complex origin of the Morasko-type meteorites than currently assumed.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2009, 1; 52-58
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of machining of EN-GJL-250 and EN-GJS-400 cast irons on tribological behavior
Autorzy:
Martinez, J.
Pereira, A.
Perez, J. A.
Mathia, T.
Powiązania:
https://bibliotekanauki.pl/articles/94140.pdf
Data publikacji:
2015
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
tribological behavior
grey cast iron
spheroidal graphite cast iron
friction
surface wear
Opis:
In transport and, particularly in the case of the present study, naval industries, one of the major objectives of research on wear and friction is focused principally on solid lubrication. In the following paper, the tribological behaviors of two well-known, different cast irons, lamellar grey iron (EN-GJL-250) and spheroidal graphite ductile iron (EN-GJS-400), are compared and the results are analyzed. For each material's family, the surfaces’ properties are characterized at different stages of the machining process. The particular influence of diverse feed rates in a turning facing is evaluated. Moreover, some tests of the laser cladding process, which contribute to the improvement of superficial properties, are carried out; therefore, the initial morphology before surface treatment is carefully characterized and evaluated in the context of subsequent adhesion qualification. The final goal of the study is to deliver feasible initial information concerning two similar cast irons that are traditionally used in the naval industry, which would be manufactured and employed in the future as dry lubricated bearings
Źródło:
Archives of Mechanical Technology and Materials; 2015, 35; 12-22
2450-9469
Pojawia się w:
Archives of Mechanical Technology and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of small amounts of aluminium on the spheroidization of cast iron with cerium mischmetal
Autorzy:
Soiński, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/382820.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metalografia
żeliwo
aluminium
sferoidyzacja
wydzielenia grafitu
metallography
cast iron
spheroidization
graphite precipitates
Opis:
The influence of aluminium (added in quantity from about 0.6% to about 2.8%) on both the alloy matrix and the shape of graphite precipitates in cast iron treated with a fixed amounts of cerium mischmetal (0.11%) and ferrosilicon (1.29%) is discussed in the paper. The metallographic examinations were carried out for specimens cut out of the separately cast rods of 20 mm diameter. It was found that the addition of aluminium in the amounts from about 0.6% to about 1.1% to the cast iron containing about 3% of carbon, about 3.7% of silicon (after graphitizing modification), and 0.1% of manganese leads to the occurrence of the ferrite-pearlite matrix containing cementite precipitates in the case of the treatment of the alloy with cerium mischmetal . The increase in the quantity of aluminium up to about 1.9% or up to about 2.8% results either in purely ferrite matrix in this first case or in ferrite matrix containing small amounts of pearlite in the latter one. Nodular graphite precipitates occurred only in cast iron containing 1.9% or 2.8% of aluminium, and the greater aluminium content resulted in the higher degree of graphite spheroidization. The noticeable amount of vermicular graphite precipitates accompanied the nodular graphite.
Źródło:
Archives of Foundry Engineering; 2012, 12, 2; 117-122
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Aluminium on the Spheroidization of Cast Iron Assessed on the Basis of Wedge Test
Autorzy:
Soiński, M. S.
Jakubus, A.
Stradomski, G.
Powiązania:
https://bibliotekanauki.pl/articles/383125.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metallography
cast iron
aluminium
spheroidization
graphite precipitates
metalografia
żeliwo
sferoidyzacja
wydzielenia grafitu
Opis:
The paper discusses the influence of aluminium in quantities from about 1.9% to about 4.7% on both the alloy matrix and the shape of graphite precipitates in cast iron spheroidized with cerium mixture (added in the quantity of 0.11%) and inoculated with ferrosilicon (1.29%). The metallographic examinations were carried out for specimens cut out of the wedge test castings (22 mm base width, 120 mm height, 180 mm length) halfway along their length. It was found that the highest susceptibility to graphitization exhibits the cast iron containing about 2.8% Al. The alloy matrices were classified and the degrees of graphite spheroidization were determined. Microscopic observations were carried out along the wedge test casting height at several places, the first distant by 20 mm from the specimen apex, the next ones every 20 mm farther. Precipitates of nodular and vermicular graphite were found in the cast iron structure. The results of examination allow to state that cast iron spheroidized in the way described here is characterised by the degree of spheroidization which increase with an increase in aluminium content within the examined range.
Źródło:
Archives of Foundry Engineering; 2013, 13, 1 spec.; 163-168
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristics of Graphite Precipitates in Aluminium Cast Iron Treated with Cerium Mixture
Autorzy:
Soiński, M. S.
Jakubus, A.
Kordas, P.
Skurka, K.
Powiązania:
https://bibliotekanauki.pl/articles/381207.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metallography
cast iron
aluminium
spheroidization
graphite precipitates
metalografia
żeliwo
sferoidyzacja
wydzielenia grafitu
Opis:
The work determined the influence of aluminium in the amount from about 1% to about 7% on the graphite precipitates in cast iron with relatively high silicon content (3.4% to 3.90%) and low manganese content (about 0.1%). The cast iron was spheroidized with cerium mixture and graphitized with ferrosilicon. The performed treatment resulted in occurring of compact graphite precipitates, mainly nodular and vermicular, of various size. The following parameters were determined: the area percentage occupied by graphite, perimeters of graphite precipitates per unit area, and the number of graphite precipitates per unit area. The examinations were performed by means of computer image analyser, taking into account four classes of shape factor. It was found that as the aluminium content in cast iron increases from about 1.1% to about 3.4%, the number of graphite precipitates rises from about 700 to about 1000 per square mm. For higher Al content (4.2% to 6.8%) this number falls within the range of 1300 – 1500 precipitates/mm2. The degree of cast iron spheroidization increases with an increase in aluminium content within the examined range, though when Al content exceeds about 2.8%, the area occupied by graphite decreases. The average size of graphite precipitates is equal to 11-15 μm in cast iron containing aluminium in the quantity from about 1.1% to about 3.4%, and for higher Al content it decreases to about 6 μm.
Źródło:
Archives of Foundry Engineering; 2015, 15, 1; 93-98
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Alloying Additions on High Temperature Interaction Between Molten Compacted Graphite Iron and Alumina
Autorzy:
Sobczak, N.
Bacior, M.
Turalska, P.
Bruzda, G.
Homa, M.
Sobczak, J. J.
Powiązania:
https://bibliotekanauki.pl/articles/354903.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
compacted graphite iron
Al2O3
sessile drop method
wettability
interface
Opis:
High temperature behavior of three compacted graphite iron (CGi) alloys on polycrystalline aluminasubstrates (99.7%, porosity <3%) were examined by the sessile drop method combined with classical contact heating procedure in flowing Ar. High-speed high-resolution CCd camera was used for continuous recording of the CGi/Al2 O3 couples during melting alloy, heating to and holding the couples at the test temperature of 1450°C for 15 min and their subsequent cooling. The comparative studies were made with conventional CGi (in wt.%: 3.70 C, 2.30 Si, 0.44 Mn, 0.054 P, 0.017 Mg, 0.015 S) and two alloys additionally containing the same amounts of 0.25 Mo, 0.1 V, 0.045 Sn and 0.032 Sb with different concentrations of Mg + Cu additions, i.e. 0.01Mg + 0.33Cu and 0.02Mg + 0.83Cu. All three CGi alloys demonstrated non-wetting behavior on the Al2 O3 substrates while the contact angle values slightly decreased with increase of the Mg + Cu content in the alloy, i.e. 131° (unalloyed CGi), 130° (0.01Mg + 0.33Cu) and 125° (0.02Mg + 0.83Cu). Structural characterization of solidified couples by light microscopy and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy revealed: 1) heterogeneous nucleation of discontinuous graphite layer at the drop-side interfaces and on the surface of the drops; 2) reactively formed Mg-rich oxide layer at the substrate-side interface; 3) the formation of satellite droplets on the surface of the drops during their solidification; 4) degeneration of initially compacted graphite to lamellar graphite after remelting and subsequent solidification of the drops, particularly in their surface layer.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 3; 1227-1238
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Treatment of Petroleum Refinery Wastewater by Graphite–Graphite Electro Fenton System Using Batch Recirculation Electrochemical Reactor
Autorzy:
Kassob, Ali Nadhum
Abbar, Ali Hussein
Powiązania:
https://bibliotekanauki.pl/articles/2202176.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
advanced oxidation process
COD removal
electro-Fenton
porous graphite
response surface methodology
Opis:
Water pollution and the lack of access to clean water are general global problems that result from the expansion of industrial and agricultural activities. Petroleum refinery wastewaters are considered as a major challenge to the environment and their treatment is mandatory. The present work investigated the removal of chemical oxygen demand (COD) from petroleum refinery effluents generated from the Al-Dewaniya petroleum refinery plant located in Iraq by utilizing a novel graphite–graphite electro-Fenton (EF) system. The electrochemical reactor was a tubular type with a cylindrical cathode made from porous graphite and concentric porous graphite rode acts as an anode. By adopting the response surface methodology (RSM), the impacts of different operating variables on the COD removal were investigated. The optimal conditions were a current density of 25 mA/cm2, FeSO4 concentration of 1.4 mM, and electrolysis time of 90 minutes, which resulted in the COD removal efficiency (RE%) of 99% at a specific energy consumption (SEC) of 10.34 kWh/kg COD. The results indicated that both current density and concentration of FeSO4 have a major impact on the elimination of COD, while time has a minor effect. The adequacy of the model equation was demonstrated by its high R2 value (0.987). The present work demonstrated that the graphite–graphite EF system could be considered as an effective approach for removing of COD from petroleum refinery wastewaters.
Źródło:
Journal of Ecological Engineering; 2022, 23, 10; 291--303
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Manufacturing of a graphite calorimeter at Yazd Radiation Processing Center
Autorzy:
Ziaie, F.
Powiązania:
https://bibliotekanauki.pl/articles/147318.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
graphite calorimeters
absorbed dose
radiation processing
self designed calorimeters (SDC)
standard calorimeter
Opis:
In this work, a few quasi-adiabatic graphite calorimeters of different dimensions are described. These calorimeters have been manufactured by ourselves and studied for accurate absorbed dose measurements in 10 MeV electron beam. In order to prove the accuracy and reliability of dose measurements with the use of the self designed graphite calorimeters (SDC), an inter comparison study was performed on these calorimeters and RisŘ's graphite calorimeters (SC, standard calorimeter) at different doses by using a Rhodotron accelerator. The comparison shows conclusively SDC of the optimal size, the results agreeing with those obtained with the SC within 1%.
Źródło:
Nukleonika; 2004, 49, 4; 159-162
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of a manufacturing technology of compacted graphite iron castings from a cupola furnace
Autorzy:
Bouska, O.
Heunisch, J.
Zadera, A.
Nedelova, K.
Kobersky, F.
Powiązania:
https://bibliotekanauki.pl/articles/382494.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
grafit zagęszczony
żeliwo sferoidalne
żeliwiak
modyfikacja
compacted graphite iron
cupola furnace
modification
Opis:
Compacted graphite iron, also known as vermicular cast iron or semiductile cast iron is a modern material, the production of which is increasing globaly. Recently this material has been very often used in automotive industry. This paper reviews some findigs gained during the development of the manufacturing technology of compacted graphite iron under the conditions in Slévárna Heunisch Brno, Ltd. The new technology assumes usage of cupola furnace for melting and is beeing developed for production of castings weighing up to 300 kilograms poured into bentonite sand moulds.
Źródło:
Archives of Foundry Engineering; 2012, 12, 1; 125-129
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Segregation of Admixing Elements in the Boundary Layer of the Main Inlet of a Ductile Iron Casting
Autorzy:
Borowiecki, B.
Mak, S.
Powiązania:
https://bibliotekanauki.pl/articles/382659.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ductile iron
nodular graphite
boundary layer
żeliwo sferoidalne
grafit sferoidalny
warstwa przyścienna
Opis:
The object of the present paper is to determine the distribution of admixing elements, such as magnesium, manganese, silicon and sulfur, in the boundary layer of the main inlet of a ductile iron casting. The authors also intend to demonstrate the influence of elements diffusing from the casting mold, such as oxygen and silica, on the chemical composition of the boundary layer of the casting.
Źródło:
Archives of Foundry Engineering; 2013, 13, 2 spec.; 10-17
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of small amounts of aluminium on the effectiveness of cast iron spheroidization with magnesium
Autorzy:
Soiński, M. S.
Jakubus, A.
Powiązania:
https://bibliotekanauki.pl/articles/379819.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metallography
aluminium
cast iron
spheroidization
graphite precipitates
metalografia
żeliwo
sferoidyzacja
wydzielenia grafitu
Opis:
The influence of aluminium added in amounts of about 1.6%, 2.1%, or 2.8% on the effectiveness of cast iron spheroidization with magnesium was determined. The cast iron was melted and treated with FeSiMg7 master alloy under industrial conditions. The metallographic examinations were performed for the separately cast rods of 20 mm diameter. They included the assessment of the shape of graphite precipitates and of the matrix structure. The results allowed to state that the despheroidizing influence of aluminium (introduced in the above mentioned quantities) is the stronger, the higher is the aluminium content in the alloy. The results of examinations carried out by means of a computer image analyser enabled the quantitative assessment of the considered aluminium addition influence. It was found that the despheroidizing influence of aluminium (up to about 2.8%) yields the crystallization of either the deformed nodular graphite precipitates or vermicular graphite precipitates. None of the examined specimens, however, contained the flake graphite precipitates. The results of examinations confirmed the already known opinion that aluminium widens the range of ferrite crystallization.
Źródło:
Archives of Foundry Engineering; 2013, 13, 3; 80-83
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena szerokości szczeliny dylatacyjnej w blokach grafitowych reaktora Maria
Assessment of the expansion provision width in the Maria reactor graphite blocks
Autorzy:
Zając, Bogdan
Olszewski, Grzegorz
Piotrowska, Natalia
Powiązania:
https://bibliotekanauki.pl/articles/107931.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
blok grafitowy
szczelina dylatacyjna
reaktor jądrowy
graphite block
expansion provision
nuclear reactor
Opis:
Przedmiotem pracy była ocena szerokości szczeliny dylatacyjnej w blokach grafitowych reaktora MARIA NCBJ po ich długotrwałej eksploatacji w reaktorze. Nominalna szerokość szczeliny dylatacyjnej bloku grafitowego przed eksploatacją w reaktorze wynosiła ok. 30 mm. W czasie długotrwałej pracy reaktora, w wyniku interakcji pomiędzy szybkimi neutronami a grafitem następuje powolne pęcznienie grafitu powodujące porowatość i pogorszenie jego własności fizycznych. Efektem pęcznienia grafitu pod wpływem oddziaływania z neutronami następuje zmniejszenie się szczeliny dylatacyjnej. Badania szerokości szczeliny dylatacyjnej przeprowadzono metodą radiograficzną. Ze względu na trudności z zastosowaniem radiografii klasycznej (bloki grafitowe były napromieniowane) do badań wykorzystano płyty obrazowe i aparaturę do badań radiografią cyfrową. Badania bloków były przeprowadzone w tzw. Komorach Gorących nad reaktorem MARIA.
The paper focuses on the assessment of the width of the expansion provision within the graphite blocks placed in MARIA nuclear reactor of the National Centre for Nuclear Research in Świerk, after their long-lasting operation in the reactor. The nominal width of the expansion provision before placing in the reactor was approximately 30mm. As a result of an interaction between the fast neutrons and the graphite within the reactor, there occurs an incremental swelling of the graphite, causing its porosity and deterioration of its physical properties. This results in narrowing of the expansion provision. Tests aimed at assessing the expansion provision were conducted with the use of radiographic testing. Due to the difficulties arising from applying classical radiographic testing (irradtiation of the graphite blocks),digital radiography instruments were employed and the testing was only possible in so called Hot Cells placed above the reactor.
Źródło:
Badania Nieniszczące i Diagnostyka; 2019, 3; 42-45
2451-4462
2543-7755
Pojawia się w:
Badania Nieniszczące i Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wear resistance of graphitized steels
Odporność grafityzowanej stali na zużycie ścierne
Autorzy:
Byelikov, S
Volchok, I.
Akimov, I
Powiązania:
https://bibliotekanauki.pl/articles/351033.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
graphitized steel
graphite inclusions
wear resistance
stal grafityzowana
wydzielenia grafitu
zużycie ścierne
Opis:
Heat-treated graphitized steels with different carbon, silicon and copper contents have been the object of study. The influence of the composition on the structure and wear resistance (weight loss of the specimen) of graphitized steels (after hardening and tempering) under the conditions of metal to metal dry sliding friction with the use of Amsler-type friction machines, has been investigated in this work. Research results have shown that the main factors affecting wear resistance of graphitized steels have been not only their metal base hardness, but the quantity, shape and distribution of graphite inclusions uniformity in the structure of such steels as well. A regression dependence of the quantity of specimen’s weight loss on carbon, silicon and copper content has been obtained in the work. The highest wear resistance was pertained by the steel having the following content: 1.60. . . 1.70%C; 2.20. . . 2.30%Si; 0.80. . . 0.90%Cu; 0.60. . . 0.70%Mn; 0.15. . . 0.18%Cr; 0.22. . . 0.25%Al; up to 0.015%S and 0.024%P.
Przedmiotem badań była grafityzowana stal (po obróbce cieplnej) o zróżnicowanej zawartości węgla, krzemu oraz miedzi. W pracy przedstawiono wyniki badań wpływu składu chemicznego grafityzowanej stali, po hartowaniu i odpuszczaniu, na jej strukturę i zużycie ścierne (zmniejszenie masy próbki) w warunkach suchego tarcia ”metal-metal” na maszynie typu Amslera. Wyniki badań świadczą o tym, że odporność na zużycie ścierne zależy nie tylko od twardości osnowy metalowej, lecz także od ilości, kształtu i jednorodności wydzieleń grafitu oraz rozkładu przestrzennego wtrąceń w strukturze stali tego typu. Otrzymano zależności regresyjne wartości ubytku masy próbek w funkcji zawartości węgla, krzemu i miedzi. Największą odpornością na zużycie ścierne wyróżniają się stale o następującym składzie chemicznym: 1,60. . .1,70% C, 2,20. . . 2,30% Si, 0,80. . . 0,90% Cu, 0,60. . . 0,70% Mn, 0,15 . .. 0,18% Cr, 0,22. . . 0,25% Al, do 0,015% S i 0,024% P.
Źródło:
Archives of Metallurgy and Materials; 2013, 58, 3; 813-816
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interactions between liquid slag and graphite during the reduction of metallic oxides
Interakcje pomiędzy ciekłymi żużlami, a grafitem w trakcie redukcji tlenków metalicznych
Autorzy:
Migas, P.
Karbowniczek, M.
Powiązania:
https://bibliotekanauki.pl/articles/353333.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
redukcja żużla
grafit
ciekły żużel
zwilżanie
slag reduction
graphite
liquid slag
wettability
Opis:
High global demand for metallic elements such as Fe, Cr, Ti, Mn leads to an intensive technological development of metal recovery. One of the ways is to recover metals from metallurgical slag. The sessile drop method was adopted in order to study the interactions between liquid slag and graphite. Steelmaking slag was used during this research. The slag used included converter slag and slag from chrome steel melting as well as their mixtures with other modifiers. The analysis covered six types of slag in the temperature ranging from 1100°C to 1600°C in the argon atmosphere. In the course of research mass spectrometry and scanning microscope were used. The following were set for the examined samples during the reduction process: liquidus temperature and the nature of interactions (wettability or its lack). It was observed that the volume of slag samples dynamically changed in the course of the reduction of metallic oxides.
Duże zapotrzebowanie dzisiejszego Świata na pierwiastki metaliczne np. Fe, Cr, Ti, Mn, powoduje bardzo intensywny rozwój technologii ich odzysku m.in. z żużli metalurgicznych. Przy użyciu techniki leżącej kropli wykonano badania współoddziaływania ciekłych żużli z grafitem. Do badań wykorzystano żużle stalownicze: konwertorowy i z wytopu stali chromowych oraz ich mieszanin z innymi modyfikatorami, analizie poddano sześć żużli w zakresie temp 1100-1600°C w atmosferze argonu. W badaniach wykorzystano również spektrometr masowy oraz mikroskop skaningowy. Określono temperaturę liquidus dla analizowanych próbek, jak również charakter interakcji - zwilżanie lub jego brak - w trakcie trwania procesu redukcji. Zaobserwowano dynamiczne zmiany objętości próbek żużlowych w trakcie zachodzenia procesu redukcji tlenków metalicznych.
Źródło:
Archives of Metallurgy and Materials; 2010, 55, 4; 1147-1157
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of over-cooling the nodular cast iron to the graphite form in the surface layer
Autorzy:
Hosadyna, M.
Dobosz, S. M.
Kusiński, J.
Powiązania:
https://bibliotekanauki.pl/articles/382407.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
żeliwo sferoidalne
moduł odlewniczy
postać grafitu
nodular cast iron
casting module
graphite form
Opis:
A cast iron is gradient material. This means that depending on the cooling rate it is possible, at the same chemical composition and the physicochemical state of molten metal, to obtain material with a different structure. The connection between the wall thickness of the casting and the speed of its cooling expresses the casting module. Along with the module escalation a cooling rate of the casting is reducing what can cause changes of the microstructure and the increased tendency to the crystallization of distorted graphite forms. Inspections of experimental castings from nodular cast iron with different modules were conducted to the graphite form.
Źródło:
Archives of Foundry Engineering; 2012, 12, 1; 43-46
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Graphite Shape in Cast Iron Obtaining by Inmold Process
Autorzy:
Gumienny, G.
Kurowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/381705.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
theory of crystallization
inmold process
graphite shape
teoria krystalizacji
technologia inmold
żeliwo sferoidalne
Opis:
The paper presents results of research on the effect of magnesium on the graphite shape in cast iron obtained by Inmold process. For testing Lamet® 5504 master alloy was used. The crystallization process of cast iron with various Mg concentrations was evaluated with use of the thermal and derivative analysis (TDA) method. The conditions were demonstrated for which a flake, vermicular and nodular graphite were obtained. Values of graphite “c” coefficient were analyzed. Results from it the significant differences between the assessment of the graphite on metallographic specimen and by the "c" coefficient. An effect of wall thickness of the casting on the graphite coefficient was indicated.
Źródło:
Archives of Foundry Engineering; 2015, 15, 3 spec.; 15-20
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of laser texturing on tribological properties of DLC coatings
Autorzy:
Radek, Norbert
Tokar, Dorota
Kalinowski, Artur
Pietraszek, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/1839527.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
DLC
laserowe teksturowanie
powłoki
właściwości tribologiczne
grafit
laser texturing
coatings
tribological properties
graphite
Opis:
The work presents the use of laser texturing of DLC coatings to improve tribological properties. The coatings were applied by the PVD method to the rings made of 4H13 steel. The surface texturing was = 343 nm.performed with the TruMICRO 5325c picosecond laser with the radiation wavelength The surface microstructure analysis, surface microgeometry and microhardness measurements and tribological tests were carried out. The problem presented in the paper can be used to extend the knowledge of the areas of application of DLC coatings, especially in sliding friction pairs.
Źródło:
Production Engineering Archives; 2021, 27, 2; 119-123
2353-5156
2353-7779
Pojawia się w:
Production Engineering Archives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling the propagation of ultrasonic guided waves in a composite plate by a spectral approximation method
Autorzy:
Zitouni, Ismaine
Rhimini, Hassan
Chouaf, Abdelkerim
Powiązania:
https://bibliotekanauki.pl/articles/38896621.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
guided waves
spectral method
dispersion curves
graphite epoxy composite
acoustic power
normalized displacement.
Opis:
Graphite-epoxy composites have been able to meet the multiple requirements of the space industry. However, the radiation from the spatial environment and non-perfect adhesion between the fibers and the matrix can lead to the appearance of imperfections. To handle this, we use non-destructive testing by ultrasonic guided waves known for its high accuracy in detecting defects. In this article, we study the propagation of ultrasonic guided waves in a graphite-epoxy composite plate by the spectral method. First, the mathematical formalism is explained for modeling guided waves in the composite material. Next, we plot the dispersion curves of the composite plate in different orientations of the fibers with a MATLAB program and the results are compared with those of the DISPERSE software. These give us information on the modes that propagate in the structure. We elaborate and explain a technique based on displacement symmetry to distinguish between the different modes. A discussion based on time-saving and accuracy is established to show the advantages of the method. The second part of our paper consists in giving a physical meaning to the spectral displacements normalized in amplitude. We propose to normalize the spectral eigenvectors by the acoustic power. We plot the displacement and stress profiles of the guided modes and we compare our results to the analytical ones. Perfect correspondence is found, indicating the accuracy of the approach developed. In addition, a study of the vibrational state in the composite plate is established for Lamb and horizontal shear modes at a specific frequency.
Źródło:
Engineering Transactions; 2023, 71, 2; 213-227
0867-888X
Pojawia się w:
Engineering Transactions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Continuous modification of cast iron by the FLOTRET method
Autorzy:
Hanus, A.
Hanusová, P.
Powiązania:
https://bibliotekanauki.pl/articles/380281.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
innowacyjne technologie odlewnicze
innowacyjne materiały odlewnicze
rozwój produktu
żeliwo sferoidalne
metoda FLOTRET
innovative foundry technologies
innovative foundry materials
product development
cast iron
spheroidal graphite
modification of graphite shape
FLOTRET method
Opis:
Increasing demands on the utility properties of materials used for castings have led to the production of cast iron with a modified shape of graphite, where the required properties are achieved by a change in graphite shape, its size and layout, and a change in the basic structure of the metal. This paper is focused on the continuous method of producing spheroidal graphite FLOTRET. In the introductory section is summarized the theoretical foundations of the secondary treatment of cast irons, especially the FLOTRET flow method, describes the advantages and disadvantages of the method. The practical part is divided into laboratory and operational tests. Laboratory experiments were conducted on a laboratory-type modifier FLOTRET chamber, which was designed and hydraulically optimized. Experiments were focused on the effects of pressure altitude and amount of modifier on the residual values of magnesium, as conditions for a successful modification. The method was tested in two foundries under operating conditions and in one of them was observed a long-term modification process.
Źródło:
Archives of Foundry Engineering; 2012, 12, 3; 43-48
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ disiarczku molibdenu i grafitu na właściwości tribologiczne wulkanizatów uwodornionego kauczuku bautadienowo-akrylonitrylowego
Influence of molybdenum disulphide and graphite on the tribological properties of vulcanizates of hydrogenated butadiene acrylonitrile copolymer
Autorzy:
Ostaszewska, U.
Magryta, J.
Lewandowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/143129.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
tarcie
guma
grafit
disiarczek molibdenu
aproksymacja
friction
rubber
graphite
molybdenum disulphide
tribology
approximation
Opis:
Przedstawiono wyniki modyfikacji składów mieszanki kauczukowej IRP1078 zawierającej kauczuk HNBR poprzez wprowadzenie do jej składu disiarczku molibdenu i mikronizowanego grafitu. Celem modyfikacji była poprawa właściwości tribologicznych wulkanizatów tej mieszanki. Stwierdzono, iż stosowanie każdego z tych modyfikatorów oddzielnie nie daje znaczącej poprawy współczynnika tarcia ani przyrostu temperatury powierzchni trących. Stosując numeryczne metody aproksymacyjne wielomianem drugiego stopnia znaleziono takie przedziały zawartości obydwu modyfikatorów, w których w wyniku synergizmu tych składników uzyskano istotną poprawę właściwości tribologicznych wulkanizatów badanej mieszanki.
The results of modification of the compositions of the rubber compound IRP 1078, HNBR-containing, with molybdenum disulphide and submicrometer graphite were presented. Improvement of the tribological properties was the aim of the modification. It was found that each of this modifiers don't give a significant improvement of the coefficients of friction and the temperature rises cause by friction. Using of the numerical approximation method (polynomial second degree) the range of the modifiers contents was found in which a synergism of this modifiers gives considerably improvement of the tribological properties of the vulcanizates.
Źródło:
Chemik; 2010, 64, 4; 254-267
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of titanium in Thin Wall Vermicular Graphite Iron Castings production
Autorzy:
Górny, M.
Kawalec, M.
Powiązania:
https://bibliotekanauki.pl/articles/381718.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
vermicular graphite
microstructure
titanium
thin walled casting
grafit wermikularny
mikrostruktura
tytan
odlewanie cienkościenne
Opis:
In this paper the effects of titanium addition in an amount up to 0.13 wt.% have been investigated to determine their effect on the microstructure and mechanical properties of Thin Wall Vermicular Graphite Iron Castings (TWVGI). The study was performed for thin-walled iron castings with 3-5 mm wall thickness and for the reference casting with 13 mm. Microstructural changes were evaluated by analyzing quantitative data sets obtained by image analyzer and also using scanning electron microscope (SEM). Metallographic examinations show that in thin-walled castings there is a significant impact of titanium addition to vermicular graphite formation. Thin-walled castings with vermicular graphite have a homogeneous structure, free of chills, and good mechanical properties. It may predispose them as a potential use as substitutes for aluminum alloy castings in diverse applications.
Źródło:
Archives of Foundry Engineering; 2013, 13, 2; 25-28
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Critical Raw Materials – What´s the Crux of the Matter?
Lista pierwiastków krytycznych – jakie są kryteria zaliczenia pierwiastków?
Autorzy:
Dvoracek, Jaroslav
Sousedikova, Radmila
Jurekova, Zdenka
Matyasova, Zuzana
Powiązania:
https://bibliotekanauki.pl/articles/318251.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
surowce krytyczne
wolfram
fluoryt
niob
grafit
critical raw materials
tungsten
fluorspar
niobium
graphite
Opis:
The paper takes into account mineral commodities that have been listed as critical by the EU Commission. It concentrates attention on the issue of global demand/supply balances, and summarizes causes for critical listing of these commodities.
W artykule przedstawiono surowce mineralne wymienione przez Komisję Europejską jako krytyczne. Koncentruje uwagę na globalnym popycie i podsumowuje przyczyny zestawienia listy pierwiastków krytycznych.
Źródło:
Inżynieria Mineralna; 2019, 21, 1/2; 97-99
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of coatings made by plasma spray and PVD methods for protecting graphite molds
Powłoki ochronne nakładane metodami natrysku plazmowego oraz PVD na grafitowe krystalizatory przemysłowe
Autorzy:
Nejman, I.
Richert, M.
Zawadzka, P.
Powiązania:
https://bibliotekanauki.pl/articles/264019.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
graphite molds
protective coatings
plasma spraying
PVD
krystalizatory grafitowe
powłoki ochronne
natrysk plazmowy
Opis:
The results of our research on the application of coatings for protecting industrial casting molds are presented. Tests were carried out on graphite molds with deposited Al2O3 coatings containing the addition of glassy carbon and with W/Zr/DLC coatings, both examined after the process of pouring molds with molten aluminum bronze. The coatings were applied by two different methods; i.e., plasma spraying in the case of Al2O3 + glassy carbon coating and PVD in the case of W/Zr/DLC coating. Reference tests were also conducted on graphite molds without coating. The use of protective coatings on graphite molds seems to be an effective solution. Studies have shown that coatings have good resistance during the casting process. The liquid metal sticking to the surface did not penetrate deep inside the graphite mold. The use of coating technology reduces the amount of downtime necessary to replace worn molds and increases the efficiency of the casting process.
W pracy przedstawiono wyniki badań dotyczące zastosowania powłok do ochrony grafitowych krystalizatorów przemysłowych. Badaniom poddano krystalizator grafitowy bez naniesionej powłoki, jak i z powłoką Al2O3 z dodatkiem węgla szklistego otrzymaną metodą natrysku plazmowego oraz krystalizator z powłoką W/Zr/DLC otrzymaną metodą PVD. Przeprowadzone badania dowodzą, że zastosowanie powłok w celu ochrony powierzchni krystalizatorów może być skutecznym rozwiązaniem. Badania wykazały, że zarówno powłoki ceramiczne Al2O3 + węgiel szklisty, jak i powłoka W/Zr-DLC zapewniają ochronę krystalizatora w trakcie kontaktu z ciekłym medium. Badania strukturalne oraz analiza składu chemicznego zostały przeprowadzane z zasto-sowaniem skaningowej mikroskopii elektronowej (HITACHI SU-70).
Źródło:
Metallurgy and Foundry Engineering; 2016, 42, 2; 95-103
1230-2325
2300-8377
Pojawia się w:
Metallurgy and Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies of physicochemical properties of graphite oxide and thermally exfoliated/reduced graphene oxide
Autorzy:
Drewniak, S. E.
Pustelny, T. P.
Muzyka, R.
Plis, A.
Powiązania:
https://bibliotekanauki.pl/articles/779581.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
graphite oxide
thermally exfoliated/reduced graphene oxide
topography investigations
Raman spectroscopy
elemental analysis
Opis:
The aim of the experimental research studies was to determine some electrical properties of graphite oxide and thermally exfoliated/reduced graphene oxide. The authors tried to interpret the obtained physicochemical results. For that purpose, both resistance measurements and investigation studies were carried out in order to characterize the samples. The resistance was measured at various temperatures in the course of composition changes of gas atmospheres (which surround the samples). The studies were also supported by such methods as: scanning electron microscopy (SEM), Raman spectroscopy (RS), atomic force microscopy (AFM) and thermogravimetry (TG). Moreover, during the experiments also the elemental analyses (EA) of the tested samples (graphite oxide and thermally exfoliated/reduced graphene oxide) were performed.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 4; 109-114
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zjawisko przenoszenia materiału w skojarzeniu grafit ekspandowany–stal
The phenomenon of transferring material in the combination of expanded graphite–steel
Autorzy:
Rewolińska, A.
Stachowiak, A.
Kinal, G.
Paczkowska, M.
Perz, K.
Powiązania:
https://bibliotekanauki.pl/articles/971367.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
tarcie
ruch posuwisto-zwrotny
przenoszenie materiału
grafit ekspandowany
friction
reciprocating
transfering material
expanded graphite
Opis:
Celem artykułu jest identyfikacja zjawiska przenoszenia materiału w skojarzeniu pary tribologicznej grafit ekspandowany–stal w wybranych warunkach. Badanie skojarzenia materiałowego wykonano na stanowisku kulka–pierścień. Stalowa kulka poruszała się ruchem posuwisto-zwrotnym po powierzchni próbki (pierścień) z grafitu ekspandowanego. Próby wykonano na sucho oraz mokro (całkowite zanurzenie skojarzenia w wodzie). Ocenę powierzchni kulki oraz pierścienia prowadzono z wykorzystaniem metalograficznego mikroskopu op-tycznego firmy ZAISS. Stwierdzono, że na powierzchni kulki, zarówno podczas pracy na sucho jak i po zanurzeniu skojarzenia w wodzie powstaje warstwa grafitu. Wygląd tworzonej warstwy zależy od warunków pracy skojarzenia–warstewka utworzona w wodzie jest cieńsza niż warstwa utworzona podczas pracy na sucho. Utworzona warstwa ma wyraźną strefową budowę warstwy. Na powierzchni bocznej kulki powstają zarysowania, których mechanizm powstawania wymaga wyjaśnienia. Należy poznać mechanizm powstawania warstwy oraz warunki kształtowania tej warstewki o optymalnych właściwościach.
A phenomenon closely related to cooperation tribological pair of graphite-metal is the transmission of the material. A large number of physical and chemical factors affecting the transfer of graphite cause the lack of theory describing this phenomenon. It also is difficult to determine which of the elementary frictions dominates under certain conditions. The aim of this article is to identify the relocation of the material in the combination tribological pair of expanded graphite-steel under the selected conditions. Research was carried out on post-ball-ring tester. A steel ball moved with a reciprocating motion over the surface of the sample (ring) of the expanded graphite. Tests were carried out in dry and wet (total immersion association in water) conditions. The evaluation of the surface of the ball and ring were conducted using optical microscopy (metallographic manual Zaiss). The surface of the balls, both in dry and after immersion associations in water, formed a layer of graphite. The exterior layer formed varied with the operating conditions of association; the layer formed in water was thinner than the layer formed in dry working conditions. The formed layer has a clearly layered structure. On the surface of the balls, cracks were found and the mechanism needs to be clarified. Wear products, which are products of reactions and removed from the workplace, had a beneficial role in this case, under appropriate conditions. There is a need to understand the mechanism of the formation of the layer and the layer forming conditions with optimal properties.
Źródło:
Tribologia; 2015, 4; 167-175
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of averaged Voronoi polyhedron in the modelling of crystallisation of eutectic nodular graphite cast iron
Autorzy:
Burbelko, A. A.
Początek, J.
Królikowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/381559.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cast iron
nodular graphite
modelling
averaged Voronoi polyhedron
żeliwo
grafit kulkowy
modelowanie
wielościan Voronoia
Opis:
The study presents a mathematical model of the crystallisation of nodular graphite cast iron. The proposed model is based on micro- and macromodels, in which heat flow is analysed at the macro level, while micro level is used for modelling of the diffusion of elements. The use of elementary diffusion field in the shape of an averaged Voronoi polyhedron [AVP] was proposed. To determine the geometry of the averaged Voronoi polyhedron, Kolmogorov statistical theory of crystallisation was applied. The principles of a differential mathematical formulation of this problem were discussed. Application of AVP geometry allows taking into account the reduced volume fraction of the peripheral areas of equiaxial grains by random contacts between adjacent grains. As a result of the simulation, the cooling curves were plotted, and the movement of "graphite-austenite" and "austenite-liquid” phase boundaries was examined. Data on the microsegregation of carbon in the cross-section of an austenite layer in eutectic grains were obtained. Calculations were performed for different particle densities and different wall thicknesses. The calculation results were compared with experimental data.
Źródło:
Archives of Foundry Engineering; 2013, 13, 1; 134-140
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Novel, Non-invasive Method for the Detection of Combustion Zone Propagation in Solid High Energy Materials by Means of Thermocouples and Pyrolytic Graphite
Autorzy:
Miszczak, M.
Świderski, W.
Panas, A. J.
Powiązania:
https://bibliotekanauki.pl/articles/358649.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
solid high energy materials
combustion zone propagation
average burning rate
thermocouples
pyrolytic graphite (pyrographite)
Opis:
This work presents a new, non-invasive method for the discrete detection of combustion zone propagation in high energy materials – pyrotechnic compositions – by means of thermocouples bonded to the external, side surface of a pyrolytic graphite (pyrographite) tube filled with the pyrotechnic composition and ignited at the one end by a CO2 laser. The thermocouples were positioned in a line parallel to the longitudinal axis of the pyrographite tube, which was used as a directional heat guide (thermal management) and a thermoresistant structure, enabling detection of the propagation of the combustion zone as a heat zone generated by the combustion, traveling on the outside surface of the pyrographite tube along its axis. Such a directional heat guidance was caused by the unique thermal conductivity anisotropy of pyrographite resulting in low thermal conductivity of the pyrographite tube along its axis and high thermal conductivity across the tube radius. The thermocouples detected passages of the outside heat zone that were equally time delayed in relation to the combustion zone inside the tube. Dividing the distance between the thermocouples by the time between their thermoelectric response to the same (corresponding) isotherm of the heat zone, gave the average burning rate of the high energy composition being tested over the distance between the thermocouples. The proposed procedure for burning rate determination was verified by numerical simulations.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 3; 417-431
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication of High-Strength Gray Cast Iron Using Permanent Magnet Scrap
Autorzy:
Park, S.-Y.
Kim, J. H.
Seo, S. J.
On, J. S.
Lim, K. M.
Powiązania:
https://bibliotekanauki.pl/articles/352204.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gray cast iron
rare earth element
Nd-Fe-B magnet scrap
graphite formation
microstructure
Opis:
In this study, we have developed the manufacturing technology for high strength gray cast irons by using the spent permanent magnet scraps. The cast specimen inoculated by using a spent magnet scraps showed the excellent tensile strength up to 306MPa. This tensile strength value is 50MPa higher than that of the specimen cast without inoculation, and is similar to that of the specimen inoculated by using the expensive misch-metal. These superior mechanical properties are attributed to complex sulfides created during solidification that promote the formation and growth of Type-A graphite. It is therefore concluded that spent magnets scrap can provide an efficient and cost-effective inoculation agent for the fabrication of high-performance gray cast iron.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 1113-1117
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Structural Parameters - the Shape of Graphite and Matrix on Change of Ultrasonic Wave Propagation Rate and Value of Attenuation in Graphitic Cast Irons
Autorzy:
Belan, Juraj
Tillová, Eva
Uhríčik, Milan
Pastierovičová, Lucia
Powiązania:
https://bibliotekanauki.pl/articles/26081550.pdf
Data publikacji:
2023
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
badanie ultradźwiękowe
zapewnienie jakości żeliwa
grafitowy kształt
współczynnik perlitu i ferrytu
ultrasonic investigation
quality assurance of cast iron
graphite shape
pearlite and ferrite ratio
quantitative evaluation of graphite and matrix
Opis:
Despite the tendency of the current industry, especially the automotive industry, it is to use modern, light and super-strong materials based on Al or HSLA steels, the application of classic materials such as cast iron still makes sense, especially concerning price and excellent castability. The article presents one of the possible ways of using the ultrasonic non-destructive method in quality control and simpli-fication of the identification of the type of cast iron concerning the change of parameters of ultrasound propagation in materials. The main criteria for assessing the quality and determining the type of graphite cast iron were considered to be the rate of propagation of ultrasound - cL and the value of attenuation , which vary depending on the shape of the graphite and matrix. Graphitic cast irons with different graphite shapes (lamellar, vermicular, and globular shapes) and a matrix with different ferrite/perlite ratios were used as experimental material. Along with the ultrasonic tests, a metallographic analysis was also performed to quantify the microstructure of cast irons.
Źródło:
Production Engineering Archives; 2023, 29, 1; 23--27
2353-5156
2353-7779
Pojawia się w:
Production Engineering Archives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A geological interpretation of geophysical self-potential anomalies in the Radzimowice Ore District, Sudetes, South-Western Poland
Autorzy:
Sobotka, J.
Farbisz-Michałek, M.
Powiązania:
https://bibliotekanauki.pl/articles/184543.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Radzimowice ore district
self-potential method
SP anomalies
graphite body
prospecting of ore deposits
Opis:
The analysis of the geophysical surveys results carried out in the Radzimowice area reveals that the anomalous zones of significant SP (self-potential) anomalies of natural SP fields do not substantially find a reflection in existing geological papers. Confrontation of existing geological elaborations with the results of SP analysis shows that the selfpotential studies expose significant elements of geological setting – i.e. run of faults, lithological boundaries, occurrence of ore mineralization – which can be helpful in clarifying the geological setting of the area. In the study, archived self-potential data were used and additionally new SP measurements were executed to justify their treatment as a valuable source of information.
Źródło:
Geology, Geophysics and Environment; 2016, 42, 4; 475-486
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elimination of Chunky Graphite in Castings with Large Thermal Points
Autorzy:
Futas, P.
Powiązania:
https://bibliotekanauki.pl/articles/383054.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ductile iron
chunky graphite
cooling rate
thermal point
żeliwo sferoidalne
szybkość chłodzenia
punkt termiczny
Opis:
The presence of the chunky graphite is unwanted in the cast iron with the spheroidal graphite for this significantly lowers the properties of the ductile iron. This shape of the graphite is formed as the result of the slow cooling rate of the castings with large thermal point and also due to the presence of the elements which suppress the formation of the spheroidal graphite and support formation of the chunky graphite. The spheroidal graphite present in the ductile iron assures the excellent mechanical properties, while the chunky graphite significantly reduces those properties of the ductile iron. Therefore it is of importance to assume conditions under which prevented is the formation of the chunky graphite. The casts were carried out under the conditions of the regular operation of the foundry and tested were various types of modifiers and inoculators and also pre-inoculators containing the elements suppressing the formation of the chunky graphite (Al, Sb a Ba). Applied were also the chromium breaker core to suppress the formation chunky graphite which was present in the structure in the places after the feeders elimination. As whole, executed were eight casts with various types of the modifiers and inoculators.
Źródło:
Archives of Foundry Engineering; 2016, 16, 4; 57-60
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metody syntez i badania właściwości grafenu
Methods of synthesis and testing properties of graphene
Autorzy:
Jonik, J.
Purchała, M.
Grajek, H.
Powiązania:
https://bibliotekanauki.pl/articles/270836.pdf
Data publikacji:
2016
Wydawca:
Centralny Ośrodek Badawczo-Rozwojowy Aparatury Badawczej i Dydaktycznej, COBRABiD
Tematy:
tlenek grafitu
tlenek grafenu
zredukowany tlenek grafenu
graphite oxide
graphene oxide
reduced graphene oxide
Opis:
Grafen i jego pochodne są materiałami o unikalnych właściwościach biochemicznych, elektrycznych, optycznych i mechanicznych, co wzbudza zainteresowanie w wielu ośrodkach badawczych. Z tego powodu, na podstawie dostępnej literatury, podjęliśmy próbę zestawienia i interpretacji wyników badań uprzednio wymienionych materiałów otrzymanych różnymi metodami. Analizując wyniki badań różnych materiałów grafenopodobnych, można przypuszczać, że najbardziej ekonomiczną metodą otrzymywania grafenu jest zmodyfikowana metoda Hummersa. Najlepszymi technikami pomiarowymi są spektroskopia Ramana i rentgenowska spektroskopia fotoelektronów. Obydwie techniki umożliwiają ocenę składu chemicznego badanych próbek oraz stopnia ich zdefektowania. W pracy przedstawiono również niektóre z licznych zastosowań tych materiałów oraz wnioski.
Graphene and its derivatives are the materials with unique biochemical, electric, optical and mechanical properties, which has aroused interest in many research centres. Therefore, on the basis of the accessible literature, we attempt to collate and interpret the results of the aforesaid materials obtained by different methods. Analysing the results for the different graphene-like materials one can suppose, that the most economical method of the graphene synthesis is the modified Hummers’ method. The most useful testing techniques are the Raman spectroscopy and the X-ray photoelectron spectroscopy. Both techniques enable the estimation of the chemical composition and the presence of defect structure in the materials. Some of the many applications of the materials and conclusions are also presented in our review.
Źródło:
Aparatura Badawcza i Dydaktyczna; 2016, 21, 2; 110-117
2392-1765
Pojawia się w:
Aparatura Badawcza i Dydaktyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compacted Graphite Iron with the Addition of Tin
Autorzy:
Gumienny, G.
Kurowska, B.
Fabian, P.
Powiązania:
https://bibliotekanauki.pl/articles/947624.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
crystallization
graphite irons
tin
cooling curve
microstructure
krystalizacja
żeliwo grafitowe
cyna
krzywa chłodzenia
mikrostruktura
Opis:
The paper presents the effect of tin on the crystallization process, microstructure and hardness of cast iron with compacted (vermicular) graphite. The compacted graphite was obtained with the use of magnesium treatment process (Inmold technology). The lack of significant effect of tin on the temperature of the eutectic transformation has been demonstrated. On the other hand, a significant decrease in the eutectoid transformation temperature with increasing tin concentration has been shown. It was demonstrated that tin narrows the temperature range of the austenite transformation. The effect of tin on the microstructure of cast iron with compacted graphite considering casting wall thickness has been investigated and described. The carbide-forming effect of tin in thin-walled (3 mm) castings has been demonstrated. The nomograms describing the microstructure of compacted graphite iron versus tin concentration have been developed. The effect of tin on the hardness of cast iron was given.
Źródło:
Archives of Foundry Engineering; 2020, 20, 3; 15-20
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Comparison of Selected Methods of Graphitizing Inoculation Applied after the Spheroidizing Treatment
Autorzy:
Gunia, P.
Soiński, M.
Powiązania:
https://bibliotekanauki.pl/articles/381150.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metallography
cast iron structure
spheroidization
nodular graphite
graphitizing inoculation
metalografia
struktura żeliwa
sferoidyzacja
grafit sferoidalny
Opis:
The work compares the effectiveness of selected methods of graphitizing inoculation applied after the spheroidization in the slender tundish ladle of 1 Mg capacity. The inoculation was carried out according to the three various options. The first one was performed simply by means of the block of inoculant inserted in the gating system of the mould, the second one started with initial inoculation by the in-stream method during the transfer of metal from the slender ladle to the pouring ladle and was completed with the secondary modification by means of the inoculant insert placed in the mould, the third one consisted in similar initial inoculation by the in-stream method during the transfer of metal from the slender ladle to the pouring ladle followed by the secondary inoculation, again by the in-stream method, applied during the pouring operation. Examination of cast iron structure allowed to find that the best results of inoculation are achieved in the case of inoculation carried out according to the Option III, though in all cases it was possible to produce cast iron of EN-GJS-400-15 grade meeting the demands of the Standard.
Źródło:
Archives of Foundry Engineering; 2012, 12, 2s; 95-99
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of load and reinforcement content on selected tribological properties of Al/SiC/Gr hybrid composites
Autorzy:
Veličković, S.
Miladinović, S.
Stojanović, B.
Nikolić, R. R.
Hadzima, B.
Arsić, D.
Powiązania:
https://bibliotekanauki.pl/articles/111714.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
aluminum alloy
hybrid composites
silicon carbide
graphite
particles
stop aluminium
węglik krzemu
grafit
kompozyty hybrydowe
Opis:
Hybrid materials with the metal matrix are important engineering materials due to their outstanding mechanical and tribological properties. Here are presented selected tribological properties of the hybrid composites with the matrix made of aluminum alloy and reinforced by the silicon carbide and graphite particles. The tribological characteristics of such materials are superior to characteristics of the matrix – the aluminum alloy, as well as to characteristics of the classical metal-matrix composites with a single reinforcing material. Those characteristics depend on the volume fractions of the reinforcing components, sizes of the reinforcing particles, as well as on the fabrication process of the hybrid composites. The considered tribological characteristics are the friction coefficient and the wear rate as functions of the load levels and the volume fractions of the graphite and the SiC particles. The wear rate increases with increase of the load and the Gr particles content and with reduction of the SiC particles content. The friction coefficient increases with the load, as well as with the SiC particles content increase.
Źródło:
Production Engineering Archives; 2018, 18; 18-23
2353-5156
2353-7779
Pojawia się w:
Production Engineering Archives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An innovative and environmentally safe method to manufacture high-quality iron castings for possible use as elements of agricultural machines
Innowacyjna i ekologiczna metoda wykonywania odlewow z zeliwa wysokojakosciowego z mozliwoscia wykorzystania w elementach maszyn rolniczych
Autorzy:
Pytel, A.
Stefanski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/792844.pdf
Data publikacji:
2011
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
ductile iron
vermicular graphite cast iron
foundry model
filter
inoculant
spheroidization
agricultural casting
agricultural machine
Opis:
The article presents the experience related with the manufacture of utility castings poured in bentonitebonded sands on a pilot stand. The technological guidelines were presented for the ductile iron castings weighing 40 kg and 10 kg. For individual castings, the mould technology has been developed, cross-sections of the gating and feeding systems were calculated, and pilot pattern equipment was designed. The results of mechanical tests and structure examinations were discussed. The work will continue within the framework of the project No. POIG.01.03.01-12-061/08-00. The technology currently developed relates to high-quality cast iron with spheroidal and vermicular graphite without and with the addition of alloying elements, including also the grade resistant to thermal fatigue. The idea is to simplify the methods used so far for the manufacture of cast iron subjected to spheroidisation or vermicularisation in a ladle and replace them with an inmould treatment. These steps are expected to improve the ecological conditions, reduce the fume and glare effects related with magnesium treatment, and improve the process economics. The innovative method, discussed in this work and developed further under the above mentioned project, can be successfully used for casting various elements of the agricultural machinery, resulting in increased mechanical properties of the cast elements, longer life on performance and improved magnesium recovery.
W artykule przedstawiono doświadczenia wykonania odlewów użytkowych w formach w masach bentonitowych na stanowisku doświadczalnym. Zaprezentowano założenia technologiczne dla odlewów z żeliwa sferoidalnego o masie 40 kg i 10 kg. Dla poszczególnych odlewów opracowano technologię formy, obliczono przekroje układu wlewowego i zasilającego wykonano omodelowanie próbne. Omówiono rezultaty przeprowadzonych prób, wytrzymałości materiału odlewów i jego struktury. Prace są w dalszym ciągu kontynuowane w ramach prowadzonego projektu: POIG.01.03.01-12-061/08-00. Rozwijana obecnie technologia dotyczy żeliwa wysokojakościowego sferoidalnego i wermikularnego bez dodatków pierwiastków stopowych, jak również z dodatkiem pierwiastków stopowych, także odpornego na zmęczenie cieplne. Ideą zagadnienia jest uproszczenie dotychczasowych metod wytwarzania odlewów z żeliwa poddawanego procesowi sferoidyzacji lub wermikularyzacji w kadzi i zastąpienie procesem sferoidyzacji w formie odlewniczej. Dzięki temu poprawiają się warunki ekologiczne, ograniczone są efekty zadymienia i efekty pirotechniczne związane z reakcją magnezu a także ekonomiką procesu. Omówiona w pracy i rozwijana innowacyjna metoda również w projekcie może był z powodzeniem wykorzystana do odlewania różnych elementów maszyn rolniczych powodując zwiększenie właściwości wytrzymałościowych odlewnych elementów, trwałości a także zwiększenia uzysku magnezu w prowadzonym procesie.
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2011, 11C
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Initial Assessment of Graphite Precipitates in Vermicular Cast Iron in the As-Cast State and after Thermal Treatments
Autorzy:
Soiński, M. S.
Jakubus, Aneta
Borowiecki, B.
Mierzwa, P.
Powiązania:
https://bibliotekanauki.pl/articles/2126913.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
vermicular cast iron
graphite precipitates
thermal treatments
austempering
żeliwo wermikularne
morfologia grafitu
obróbka termiczna
hartowanie
Opis:
The purpose of the work was to determine the morphology of graphite that occurs in vermicular cast iron, both in the as-cast state and after heat treatment including austenitization (held at a temperature of 890°C or 960°C for 90 or 150 min) and isothermal quenching (i.e. austempering, at a temperature of 290°C or 390°C for 90 or 150 min). In this case, the aim here was to investigate whether the heat treatment performed, in addition to the undisputed influence of the cast iron matrix on the formation of austenite and ferrite, also affects the morphology of the vermicular graphite precipitates and to what extent. The investigations were carried out for the specimens cut from test coupons cast in the shape of an inverted U letter (type IIb according to the applicable standard); they were taken from the 25mm thick walls of their test parts. The morphology of graphite precipitates in cast iron was investigated using a Metaplan 2 metallographic microscope and a Quantimet 570 Color image analyzer. The shape factor F was calculated as the quotient of the area of given graphite precipitation and the square of its perimeter. The degree of vermicularization of graphite was determined as the ratio of the sum of the graphite surface and precipitates with F <0.05 to the total area occupied by all the precipitations of the graphite surface. The examinations performed revealed that all the heat-treated samples made of vermicular graphite exhibited the lower degree of vermicularization of the graphite compared to the corresponding samples in the as-cast state (the structure contains a greater fraction of the nodular or nearly nodular precipitates). Heat treatment also caused a reduction in the average size of graphite precipitates, which was about 225μm2 for the as-cast state, and dropped to approximately 170-200 μm2 after the austenitization and austempering processes.
Źródło:
Archives of Foundry Engineering; 2021, 21, 4; 131--136
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlations between Structures of Expanded Graphite - Polymer Composites and Acoustic Emission Phenomena
Korelacje pomiędzy strukturą kompozytów grafit ekspandowany-polimer a zjawiskami emisji akustycznej
Autorzy:
Berdowska, A.
Berdowski, J.
Aubry, F.
Powiązania:
https://bibliotekanauki.pl/articles/355731.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
compressed expanded graphite
polymer
composite
acoustic emission parameters
grafit ekspandowany
polimer
kompozyty
parametry emisji akustycznej
Opis:
Compressed expanded graphite was applied as a base matrix to the preparation of microporous composites as products of impregnation, polymerization and carbonization of poly-furfuryl alcohol. During carbonization, the original polymeric structure is transformed into an amorphous turbostratic carbon structure with ultramicropores. The structure, porosity and many chemical and physical properties change after each stage of their technological treatment. The acoustic emission method was used for accurate determination of these changes. It is possible to determine a large number of acoustic emission parameters and therefore to increase the amount of information provided by the studied materials. Acoustic emission pulses, counts rate, events rate, signal peak value and their sums were measured. Also frequency spectrum was received as a result of acoustic emission signal analysis with use of Fourier transformation procedure. The conclusions resulting from the Fourier analysis of the registered spectrum are very interesting and provide information about composite structures as well as bonds between the graphite matrix and the polymer that fills it. Analysis of acoustic emission parameters provides data on physical and chemical processes that would be very difficult to study by means of other techniques. Wide applications of these porous composites make them very interesting subject of the study.
Sprasowany grafit ekspandowany użyto jako bazową matrycę do wytworzenia mikroporowatych kompozytów będących produktami impregnacji, polimeryzacji i karbonizacji alkoholu polifurfurylowego. Podczas procesu karbonizacji oryginalna struktura polimerowa jest przekształcana w strukturę turbostratyczną węgla amorficznego z ultramikroporami. Struktura, porowatość oraz wiele chemicznych i fizycznych własności ulega zmianie na poszczególnych etapach technologicznego procesu. Metodę emisji akustycznej użyto w celu dokładnego przebadania tych zmian. Możliwym jest wyznaczenie w eksperymentach dużej liczby parametrów emisji akustycznej co pozwala uzyskać dużą ilość informacji o badanych materiałach. Zmierzono następujące parametry emisji akustycznej: szybkość zliczeń, szybkość zdarzeń, amplituda impulsu, średnia wartość skuteczna sygnałów oraz sumy tych parametrów. Także analizowano widmo częstotliwościowe sygnałów przy pomocy transformaty Fouriera. Wnioski wynikające z analizy fourierowskiej widm są niezwykle interesujące i dostarczają informacje o strukturze kompozytów oraz o wiązaniach między grafitową matrycą a polimerem wypełniającym ją. Analiza parametrów emisji akustycznej dostarcza wielu danych o fizycznych i chemicznych własnościach, które byłyby bardzo trudne do zbadania przy użyciu innych metod. Szerokie zastosowania omawianej grupy porowatych kompozytów czyni je bardzo interesującym przedmiotem badań.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 4; 2479-2484
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Redukcja fluorowanego grafitu (CF)n w fali spalania i charakterystyka produktów reakcji
Self-sustaining reductive defluorination of (CF)N and characterization of reaction products
Autorzy:
Cudziło, S.
Huczko, A.
Szala, M.
Bystrzejewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/208415.pdf
Data publikacji:
2006
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
synteza spaleniowa
rozwarstwiony grafit
nanostrukturalne węgliki i krzemki
combustion synthesis
exfoliated graphite
carbides
silicides
nanostructures
Opis:
Badano proces spalania mieszanin fluorowanego grafitu (CF)n z różnymi reduktorami: NaN₃, B, Ti, ZrTi, Si, CaSi₂, AlSi, TiSi, MoSi₂ i CrSi₂. Okazało się, że reakcje pomiędzy tymi substratami są dostatecznie szybkie i egzotermiczne, aby proces redukcyjnego defluorowania przebiegał w reżimie samopodtrzymującej się, wysokotemperaturowej syntezy. Wykonano pomiary ciepła reakcji oraz zbadano skład fazowy i mikrostrukturę skondensowanych produktów spalania. Obserwacje mikroskopowe ujawniły obecność rozwarstwionego grafitu we wszystkich próbkach. Nanometryczne struktury w formie włókien, prętów i krystalitów 3D także wykryto w większości produktów reakcji.
Mixtures of fluorinated graphite (CF)n with different reductants, such as NaN₃, B, Ti, ZrTi, Si, CaSi₂, AlSi, TiSi, MoSi₂, and CrSi₂ were investigated. Reactions between these substrates are fast and exothermic enough to proceed in a high temperature self-sustaining regime. Heat effects accompanying the reactions were measured and the solid reaction products were analyzed. SEM observation revealed the presence of exfoliated graphite in each case. Nanostructures, like nanofibers, nanorods, nanospheres and nano-sized crystals, were also present in most of the products. Phase (XRD) and elemental composition as well as porous structure (N₂ adsorption) of chosen reaction products were also determined.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2006, 55, 4; 257-265
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Approximation of Ausferrite Content in the Compacted Graphite Iron with the Use of Combined Techniques of Data Mining
Autorzy:
Regulski, K.
Wilk-Kołodziejczyk, D.
Kacprzyk, B.
Gumienny, G.
Rojek, G.
Mrzygłód, B.
Powiązania:
https://bibliotekanauki.pl/articles/379587.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
information technologies
foundry
graphite irons
compacted
ausferrite
data mining
regression
odlewnictwo
technologie informacyjne
zagęszczanie
żeliwo grafitowe
Opis:
This article presents the methodology for exploratory analysis of data from microstructural studies of compacted graphite iron to gain knowledge about the factors favouring the formation of ausferrite. The studies led to the development of rules to evaluate the content of ausferrite based on the chemical composition. Data mining methods have been used to generate regression models such as boosted trees, random forest, and piecewise regression models. The development of a stepwise regression modelling process on the iteratively limited sets enabled, on the one hand, the improvement of forecasting precision and, on the other, acquisition of deeper knowledge about the ausferrite formation. Repeated examination of the significance of the effect of various factors in different regression models has allowed identification of the most important variables influencing the ausferrite content in different ranges of the parameters variability.
Źródło:
Archives of Foundry Engineering; 2017, 17, 3; 117-122
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Copper in Ausferritic Compacted Graphite Iron
Autorzy:
Gumienny, G.
Kacprzyk, B.
Powiązania:
https://bibliotekanauki.pl/articles/381542.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
theory of crystallization
compacted graphite iron
ausferrite
DTA method
teoria krystalizacji
stop żelaza
ausferyt
metoda DTA
Opis:
This paper shows how it is possible to obtain an ausferrite in compacted graphite iron (CGI) without heat treatment of castings. Vermicular graphite in cast iron was obtained using Inmold technology. Molybdenum was used as alloying additive at a concentration from 1.6 to 1.7% and copper at a concentration from 1 to 3%. It was shown that ausferrite could be obtained in CGI through the addition of molybdenum and copper in castings with a wall thickness of 3, 6, 12 and 24 mm. Thereby the expensive heat treatment of castings was eliminated. The investigation focuses on the influence of copper on the crystallization temperature of the graphite eutectic mixture in cast iron with the compacted graphite. It has been shown that copper increases the eutectic crystallization temperature in CGI. It presents how this element influences ausferrite microhardness as well as the hardness of the tested iron alloy. It has been shown that above-mentioned properties increases with increasing the copper concentration.
Źródło:
Archives of Foundry Engineering; 2018, 18, 1; 162-166
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Initial Assessment of Abrasive Wear Resistance of Austempered Cast Iron with Vermicular Graphite
Wstępna ocena odporności na ścieranie żeliwa z grafitem wermikularnym hartowanego izotermicznie
Autorzy:
Soiński, M. S.
Jakubus, A.
Powiązania:
https://bibliotekanauki.pl/articles/351080.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cast iron
vermicular graphite
austempering
abrasive wear resistance
żeliwo
grafit wermikularny
odporność na ścieranie
hartowanie izotermiczne
Opis:
The work compares the abrasive wear resistance of cast iron containing vermicular graphite, measured in the as-cast state and after austempering carried out at 290°C, 340°C, or 390°C. Theexaminations were performed by means of the T-01M tribological tester using the pin-on-disc configuration. Specimens used for examinations were taken from the end tabs of the tensile specimens, these being cut out of the test walls of the double-leg keel block test castings. Examinations proved that the austempering process increases the abrasive wear resistance of vermicular cast iron by several times as compared with the as-cast material. A tendency for a slight decrease in abrasive wear with an increase in austempering temperature can be stated. The coefficient of friction took a little higher values for cast iron after thermal treatment than for the as-cast material. The work was completed with roughness examination by means of electron scanning microscopy.
W pracy porównano odporność na ścieranie żeliwa z grafitem wermikularnym w stanie lanym oraz po hartowaniu izotermicznym przeprowadzonym w temperaturach 290°C, 340°C i 390°C. Badaniaodporności na ścieranie przeprowadzono przy użyciu zestawu trybologicznego T-01M typu trzpień-tarcza. Próbki do badań pochodziły z próbek wytrzymałościowych wyciętych ze ścianek badawczych wlewków próbnych w kształcie odwróconej litery „U”. Badania wykazały, że poddanie żeliwa wermikularnego hartowaniu izotermicznemu prowadzi do kilkukrotnego wzrostu odporności tworzywa na ścieranie w porównaniu z żeliwem w stanie lanym. Zaobserwowano niewielki spadek zużycia wraz ze wzrostem temperatury hartowania. Współczynnik tarcia dla żeliwa po obróbce cieplej przybrał nieco większe wartości aniżeli w przypadku żeliwa w stanie lanym. W ramach pracy wykonano także badania chropowatości z wykorzystaniem mikroskopii skaningowej.
Źródło:
Archives of Metallurgy and Materials; 2014, 59, 3; 1073-1076
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface Treatment And Modification Of Graphene Using Organosilane And Its Thermal Stability
Obróbka powierzchniowa i modyfikacja grafenu przy użyciu organosilanu i jego stabilność termiczna
Autorzy:
Kim, D.-S.
Dhand, V.
Rhee, K.-Y.
Park, S.-J.
Powiązania:
https://bibliotekanauki.pl/articles/354056.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
graphite
thermal properties
Raman spectroscopy
surface treatment
3-APTES
grafit
właściwości termiczne
spektroskopia Ramana
obróbka powierzchniowa
Opis:
In this study, graphene was functionalized via acid oxidation in the presence of a mixture of concentrated sulfuric acid and nitric acid. The oxidized graphene was silanized using the coupling agent, 3-aminopropyltriethoxsilane, resulting in functionalized graphene. The oxidized graphene and functionalized graphene were characterized by X-Ray diffraction, Fourier transform infrared spectroscopy, High-resolution micro Raman spectroscopy, thermogravimetric analysis, and atomic force microscopy to confirm the presence of functional moieties on the graphene surface. Thermal studies also demonstrate that the functionalized material is thermally stable up to higher temperatures.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1387-1391
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of the Quality of Ductile Cast Iron EN-GJS-500-7 Through the Influence of its Chemical Composition on the Grain Composition of Spheroidal Graphite
Autorzy:
Pacha-Gołębiowska, Halina
Powiązania:
https://bibliotekanauki.pl/articles/2203940.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ductile cast iron
chemical composition
graphite precipitates
stereological parameters
żeliwo sferoidalne
skład chemiczny
grafit
parametry stereologiczne
Opis:
Quantitative evaluation of the microstructure obtained in a product is nowadays commonly required both in R&D activities and during routine quality control of materials and components. This paper presents an assessment of the quality of ductile cast iron, based on investigations of the effect of chemical composition on the distribution of ductile graphite precipitates in low-alloy cast iron EN-GJS-500-7. The size of graphite precipitates was expressed in terms of equivalent cross-sectional diameter, which made it possible to describe the distribution of graphite precipitates with a function simulating the log-normal distribution of graphite. The resulting U, W and Z parameters were statistically analysed, including the effect of chemical composition on graphite distribution. In the studied cast iron, the components that increase the U parameter are silicon, manganese and phosphorus, thus favourably affecting the total graphite number. In contrast, the constituents that decrease the U parameter are carbon, chromium and aluminium.
Źródło:
Archives of Foundry Engineering; 2022, 22, 4; 85--89
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Insercja litu w materiały kompozytowe krzem/grafit otrzymane w wyniku mielenia wysokoenergetycznego
Synthesis and characterization of graphite/silicon composites for energy storage in lithium batteries
Autorzy:
Lota, G.
Walkowiak, M.
Lota, K
Powiązania:
https://bibliotekanauki.pl/articles/142961.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
ogniwo litowo-jonowe
kompozyty grafit/ krzem
mielenie wysokoenergetyczne
Li-ion batteries
silicon/graphite composites
Ball milling
Opis:
Kompozyty grafit/krzem mogą być stosowane jako elektrody ujemne w akumulatorach litowo-jonowych. Kompozyty zawierające dodatek krzemu w ilości od 5 do 50% zostały przygotowane w procesie mielenia wysokoenergetycznego i przebadane w celu określenia ich właściwości fizykochemicznych. Wykazano degradacyjny wpływ mielenia na strukturę obu komponentów kompozytu, co powodowało wzrost nieodwracalnej pojemności materiałów kompozytowych. Materiał kompozytowy zawierający 20% krzemu charakteryzował się najwyższymi pojemnościami, ok. 300 mAh•g-1 w 50. cyklu wyładowania. Wzrost pojemności takiej elektrody uzyskano dzięki ograniczeniu potencjału końca ładowania (EOCP) do 15 mV vs Li/Li+.
Graphite/silicon composites have been prepared by a high energy ball milling. Si content varied from 5 to 50% in relation to the whole material. All composites have been characterized physicochemically by X-ray diffraction and SEM observations. Impact of ball-milling on the formation of C/Si composites and structural degradation of their components has been studied and discussed. It has been demonstrated that ball-milling process generates a high degree of structural disorder in single components as well as in composites which is evidenced by a high irreversible capacities observed in electrochemical experiments. Composite anode material with 20% content of silicon seems to be optimal from all the tested samples, delivering the reversible capacity of 293 mAh/g in 50th charge/ discharge cycle. Improved cyclic performance has been observed when electrochemical lithium insertion cut-off voltage was set as 15 mV vs. Li/Li+.
Źródło:
Chemik; 2013, 67, 11; 1130-1137
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza zawartości siarki w masach z żywicami furanowymi
Analysis of the sulphur content in moulding sands with furan resins
Autorzy:
Holtzer, M.
Kmita, A.
Roczniak, A.
Powiązania:
https://bibliotekanauki.pl/articles/391598.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa
Tematy:
żywica furanowa
siarka
degradacja grafitu
masa formierska
furan resin
sulphur
degradation of graphite forms
moulding sands
Opis:
Masy z żywicami furanowymi należą do najszerzej stosowanych spośród mas ze spoiwami organicznymi, jeżeli chodzi o wykonywanie odlewów ze stopów żelaza. Wynika to z szeregu zalet tych mas. Jednak masy z żywicami furanowymi wykazują również pewne niedoskonałości, które są przyczyną wad w odlewach. Należą do nich obecność azotu, siarki czy fosforu w spoiwie, które to pierwiastki z masy przechodzą do metalu. Dodatkowo producenci żywic furanowych muszą ograniczać zawartość wolnego alkoholu furfurylowego do wartości <25% wag., ze względu na jego toksyczne właściwości. Szczególną uwagę należy zwracać na obecność w masie formierskiej siarki, gdy wykonuje się odlewy z żeliwa z grafitem sferoidalnym lub wermikularnym. Bardzo często występuje wtedy zjawisko degradacji tych form grafitu do grafitu płatkowego. W artykule przeprowadzono obliczenia ilości siarki, jakie są wprowadzane do masy formierskiej wraz ze spoiwem, w zależności od składu kwaśnego katalizatora (głównymi jego składnikami są najczęściej różne organiczne kwasy sulfonowe), co powinno pomóc przy wyborze katalizatora dla danej żywicy furanowej.
Among various sands with organic binders, moulding sands with furan resins belong to the group most widely applied in the manufacture of castings from ferrous alloys. This is due to a number of undisputable advantages offered by these sands, although they are not free from certain drawbacks, which ultimately can result in casting defects. The main disadvantage of furan resin sands is the fact that the binder contains nitrogen, sulphur and phosphorus, and all these elements are transferred in the course of casting from sand to metal. Additionally, producers of furan resins are forced to reduce the free furfuryl alcohol content to <25 wt. %, due to its toxic properties. Special attention deserves the presence of sulphur in moulding sand when castings are made from the cast iron with nodular or vermicular graphite. Then, as very often occurs, the effect of degradation of these two graphite forms take the shape of flake graphite. The study shows how to calculate the amount of sulphur introduced into the moulding sand together with binder, related to the acid catalyst composition (most often, its main components are various organic sulphonic acids). It is expected that the results will be useful in the selection of an optimum catalyst for a given type of furan resin.
Źródło:
Prace Instytutu Odlewnictwa; 2015, T. 55, nr 2, 2; 19-28
1899-2439
Pojawia się w:
Prace Instytutu Odlewnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of modification effect on prototype castings from GJV using ultrasound checking
Autorzy:
Skrbek, B.
Bouška, O.
Nedělová, K.
Heunisch, J.
Powiązania:
https://bibliotekanauki.pl/articles/380179.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
żeliwo
grafit wermikularny
badanie ultradźwiękowe
cast iron
vermicular graphite
ultrasound checking of structure
plausibility of results
Opis:
Reason for and risks of using of cast iron with vermicular graphite for typical construction parts. Ultrasound checking of graphite shape. Factors influencing plausibility of result. Difference between laboratory and operation application. Roughness, parallelism, stability and size dimension of walls. Conditions, proposals for simplification and productivity enhancement of castings checking.
Źródło:
Archives of Foundry Engineering; 2012, 12, 3; 105-110
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nanokompozyty termoplastycznego poliuretanu wzmacniane napełniaczami węglowymi
Thermoplastic polyurethane-based nanocomposites reinforced with carbon fillers
Autorzy:
Stafin, K.
Leszczyńska, A.
Pielichowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/1207962.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
nanotechnologia
termoplastyczny poliuretan
nanorurki węglowe
grafen
ekspandowany grafit
nanotechnology
thermoplastic polyurethane
carbon nanotubes
graphene
expanded graphite
Opis:
Termoplastyczny poliuretan (TPU) łączy w sobie właściwości usieciowanych chemicznie kauczuków w temperaturze użytkowania oraz tworzyw termoplastycznych w warunkach przetwórstwa w podwyższonej temperaturze. W niniejszej pracy przedstawiono nanokompozyty tego materiału wzmacniane napełniaczami węglowymi, takimi jak nanorurki węglowe, grafen i ekspandowany grafit. Nanododatki węglowe istotnie poprawiają właściwości polimeru, w tym wytrzymałość mechaniczną oraz stabilność termiczną, a także umożliwiają wytwarzanie nanokompozytów przewodzących ładunki elektryczne. Poprawa lub uzyskanie nowych właściwości zależy nie tylko od ilości i sposobu wprowadzania nanonapełniacza do osnowy polimeru, ale również od występowania specyficznych oddziaływań pomiędzy nanonapełniaczem a segmentami sztywnymi i miękkimi TPU. Z tego względu, dobór i modyfikacja budowy chemicznej napełniacza lub TPU są kluczowe dla uzyskania pożądanych cech użytkowych tworzywa.
Thermoplastic polyurethane (TPU) behaves both as a crosslinking rubber and thermoplast at ambient temperature during use and at elevated processing temperature, respectively. In this paper, thermoplastic polyurethane reinforced with carbon nanofillers (e.g. carbon nanotubes, graphene and expanded graphite) was presented. Carbon nanofillers improve mechanical strength, thermal stability and are effective modifiers for manufacturing electrically conductive nanocomposites. Improved or new properties of TPU nanocomposites depend not only on the amount of filler and the method of its incorporation into the polymer matrix, but also on the occurrence of a specific interactions between the filler and rigid or soft TPU segments. Therefore the proper selection and modification of chemical structure of the polymer and filler are crucial for the successful manufacturing of new material with desired properties.
Źródło:
Chemik; 2016, 70, 11-12; 685-690
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation between shape factor and mechanical properties of graphitic cast irons
Autorzy:
Vasko, A.
Vasko, M.
Powiązania:
https://bibliotekanauki.pl/articles/973009.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
shape factor
cast iron
graphite
microstructure
mechanical properties
współczynnik kształtu
żeliwo
grafit
mikrostruktury materiałów
właściwości mechaniczne
Opis:
The evaluation of shape factor (circularity) is a subject of interest in many fields of applications such as medicine and industrial processes. The shape factor plays an important role in materials science as a way to understand the relationship between microstructure and mechanical properties of technical materials. The paper deals with measurement of shape factor of graphitic particles with the aim to understand the influence of microstructure (especially shape of graphite) on mechanical properties of graphitic cast irons.
Źródło:
Production Engineering Archives; 2016, 11, 2; 11-14
2353-5156
2353-7779
Pojawia się w:
Production Engineering Archives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ temperatury na zjawiska tribologiczne występujące w skojarzeniu grafit ekspandowany–stal
The effect of temperature on the tribological phenomenon occurring in combination expanded graphite–steel
Autorzy:
Rewolińska, A.
Paczkowska, M.
Perz, K.
Orłowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/971366.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
tarcie
grafit ekspandowany
stalowa tarcza
współczynnik tarcia
zużycie
friction
expanded graphite
steel shield
friction coefficient
wear
Opis:
Celem niniejszego opracowania jest ocena wpływu temperatury na właściwości tribologiczne skojarzenia grafit ekspandowany–stalowa tarcza. Badane skojarzenie składa się z próbek wykonanych z grafitu ekspandowanego, które współpracowały z tarczą wykonaną ze stali wysokowęglowej. Próbki wykonano z grafitu ekspandowanego w postaci taśmy, która została sprasowana. Parametry chropowatości tarczy są następujące: Ra = 2,233 μm, Rz = 15,608 μm, Rq = 2,736 μm. Badania wykonywano w różnych temperaturach. Czas trwania testu wynosił odpowiednio 30 i 60 s, a prędkość poślizgu 25 mm/s. Po zakończeniu każdego z etapów próbki ważono. Na podstawie przeprowadzonych testów określano wartości współczynnika tarcia oraz szybkość zużycia masowego próbek. W wyniku współpracy tribologicznej skojarzenia odnotowano spadek współczynnika tarcia wraz ze wzrostem temperatury. Uzyskane wartości współczynnika tarcia dla próbek wykonanych z grafitu ekspandowanego są niższe niż dla grafitu proszkowego. W zakresie stosowanych nacisków wynoszących 50 i 100 N/cm2 nie odnotowano ich wpływu na współczynnik tarcia. Wykonane badania zużycia masowego próbek wskazują na potrzebę wydłużenia czasu badania. Odnotowania wymaga również fakt powstającej na powierzchni stalowej skojarzenia warstewki, która jest charakterystyczna dla współpracy stali z grafitem.
The aim of this article is to evaluate the effect of temperature on the tribological properties of expanded graphite works with a steel shield. The examined association was composed of samples made from expanded graphite, which cooperated with a shield made of high carbon steel. The values of roughness of the disc are as follows: Ra = 2.233 μm, Rz = 15.608 μm, and Rq = 2.736 μm. Tests were performed at different temperatures. The durations of the tests were 30 and 60 seconds, and the sliding velocity was 25 mm/s. After each step, the samples were weighed. Based on the tests, the coefficient of friction and wear rate of the samples were determined. The tribological combination decreased the coefficient of friction with increasing temperature. The resulting coefficients of friction for specimens made of expanded graphite were lower than the graphite powder. In the field of applied pressures of 50 and 100 N/cm2, there was no effect on the coefficient of friction. A layer was formed on the surface of the steel, which is characteristic of graphite cooperation with steel.
Źródło:
Tribologia; 2015, 4; 159-166
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The tribological characteristics of Al-Si/graphite composite
Charakterystyka tribologiczna kompozytu Al-Si/grafit
Autorzy:
Walczak, M.
Zwierzchowski, M.
Bieniaś, J.
Caban, J.
Powiązania:
https://bibliotekanauki.pl/articles/190194.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
aluminium matrix composite
graphite
sliding friction
wear testing
aluminiowe materiały kompozytowe
grafit
tarcie ślizgowe
testy zużycia
Opis:
The paper presents the results of tribological research on AlSi12CuNiMg/5.7 wt.% Gr aluminium composite material (containing graphite particles in the amount of 5.7% wt.%) and on its matrix. This composite is used as high-tech construction material in the automotive industry, particularly for pistons, cylinder liners, and slide bearings. The tribological properties of these materials can be significantly changed as a result of the introduction of graphite particles. Therefore, wear tests have been carried out using the ball-on-disc tribometer. Microstructure and wear resistance of the matrix and composite alloy have been subjected to comparative analysis. It was demonstrated that the composite reinforced with graphite is characterized by a lower friction coefficient and lower wear in comparison to the matrix.
Artykuł przedstawia wyniki badań tribologicznych aluminiowego materiału kompozytowego AlSi12CuNiMg/5.7 wt.% Gr (zawierającego cząsteczki grafitu w ilości 5,7% wag.) i jego osnowy. Kompozyt ten znajduje zastosowanie jako nowoczesny materiał konstrukcyjny w przemyśle motoryzacyjnym, szczególnie na tłoki, tuleje cylindrowe i łożyska ślizgowe. Wprowadzenie cząstek grafitu znacząco może zmieniać właściwości tribologiczne tych materiałów. W tym celu wykonano testy zużycia na tribometrze typu kula-tarcza. Mikrostruktura i odporność na zużycie stopu osnowy i kompozytu zostały poddane analizie porównawczej. Wykazano, że kompozyt zbrojony grafitem charakteryzuje się mniejszym współczynnikiem tarcia i mniejszym zużyciem w porównaniu z osnową.
Źródło:
Tribologia; 2017, 271, 1; 97-104
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł

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