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Tytuł:
Directional solidification of ledeburite
Autorzy:
Trepczyńska-Łent, M.
Powiązania:
https://bibliotekanauki.pl/articles/382901.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
solidification process
ledeburite
directional solidification
structure
interfacial distance
proces krzepnięcia
ledeburyt
krzepnięcie kierunkowe
struktura
odległość międzyfazowa
Opis:
Directional solidification of ledeburite was realised out using a Bridgman’s device. The growth rate for movement sample v=83.3 μm/s was used. In one sample the solidification front was freezing. The value of temperature gradient in liquid at the solidification front was determined. Interfacial distance λ on the samples was measured with NIS-Elements application for image analysis.
Źródło:
Archives of Foundry Engineering; 2013, 13, 3; 101-106
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solid-liquid interface morphology of white carbide eutectic during directional solidification
Autorzy:
Trepczyńska-Łent, M.
Powiązania:
https://bibliotekanauki.pl/articles/354873.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
solid-liquid interface
directional solidification
front solidification
white carbide eutectic
Opis:
In this paper the analysis of solid-liquid interface morphology in white carbide eutectic was made. In a vacuum Bridgman-type furnace, under an argon atmosphere, directionally solidified sample of Fe - C alloy was produced. The pulling rate was v = 125 μm/s (450 mm/h) and constant temperature gradient G = 33.5 K/mm. The microstructure of the sample was frozen. The microstructure of the sample was examined on the longitudinal section using an light microscope and scanning electron microscope.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 1; 365-368
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solidification of Ledeburite Eutectic
Autorzy:
Trepczyńska-Łent, M.
Powiązania:
https://bibliotekanauki.pl/articles/379998.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ledeburite eutectic
solidification
kinetics
ledeburyt
krzepnięcie
kinetyka
Opis:
The ledeburite eutectic is one from the most commercial eutectics of group the quasi-regular eutectics. The paper presents the knowledge of growth this eutectic. In the case high solidification, the foundation near which formulate the right growth eutectic they are fulfilled.
Źródło:
Archives of Foundry Engineering; 2012, 12, 2s; 71-74
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solidification Mechanism of the D-Gun Sprayed Fe-Al Particles
Autorzy:
Wołczyński, W.
Senderowski, C.
Fikus, B.
Panas, A. J.
Powiązania:
https://bibliotekanauki.pl/articles/351306.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spraying
rapid solidification
Fe-Al droplets
solidification model
Opis:
The detonation gas spraying method is used to study solidification of the Fe-40Al particles after the D-gun spraying and settled on the water surface. The solidification is divided into two stages. First, the particle solid shell forms during the particle contact with the surrounding air / gas. Usually, the remaining liquid particle core is dispersed into many droplets of different diameter. A single Fe-Al particle is described as a body subjected to a rotation and finally to a centrifugal force leading to segregation of iron and aluminum. The mentioned liquid droplets are treated as some spheres rotated freely / chaotically inside the solid shell of the particle and also are subjected to the centrifugal force. The centrifugal force, and first of all, the impact of the particles onto the water surface promote a tendency for making punctures in the particles shell. The droplets try to desert / abandon the mother-particles through these punctures. Some experimental evidences for this phenomenon are delivered. It is concluded that the intensity of the mentioned phenomenon depends on a given droplet momentum. The droplets solidify rapidly during their settlement onto the water surface at the second stage of the process under consideration. A model for the solidification mechanism is delivered.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 4; 2391-2397
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Change of aluminum alloys structure by sono-solidification
Autorzy:
Gnapowski, S.
Tsunekawa, Y.
Okumiya, M.
Lenik, K.
Powiązania:
https://bibliotekanauki.pl/articles/382741.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasonic vibration
sono solidification
Al-Si alloy
grain size
solidification temperature
drgania ultradźwiękowe
krzepnięcie
stop Al-Si
wielkość ziarna
temperatura krzepnięcia
Opis:
This experiment utilized five Aluminum alloys with silicon content percentages of 7, 10, 12.6, 14.5 and 17(wt)%. Ultrasonic vibration was applied to improved the quality of aluminum alloys. Sono-solidification, in which ultrasound vibrations are applied to molten metal during its solidification, is expected to cause improved mechanical properties due to grain refinement. Observed by microstructure photographs was that grains became smaller and their shapes more regular. Using ultra sound solidification α Al appeared during ultrasound treatment the eutectic solidification time was longest around 10% compared with same condition experiment without ultrasound treatment.
Źródło:
Archives of Foundry Engineering; 2013, 13, 4; 39-42
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation the Solidification/Stabilization of Heavy Metals by Portland Cement
Autorzy:
Al-Kindi, Ghayda Yaseen
Powiązania:
https://bibliotekanauki.pl/articles/124334.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
solidification/stabilization
binder
cement
leaching
hazards waste
Opis:
Numerous solutions are used in the site to treat pollution, including remediation of heavy metals and hazardous wastes by solidification/stabilization (S/S) with cement as a binder. S/S is one of the most commonly methods used for treating inorganic wastes. The objective of this research was using unconfined compressive strength test, and EPA Toxicity Leaching Procedure TCLP method 1313, to test the effectiveness performance, and efficiency of the solidification/stabilization method for treatment of some heavy metals (Fe, Zn, Mn, Cr) contaminated sands using ordinary locally produced Portland Cement type A. In this study, three loads of pollution in three mix designs by contaminated sands were used. As a result of the unconfined compression test, it was observed that the value 1–15 MPa with OPC cement content 25% in the solidification/stabilization process was good enough to comply with the limited value set by the (US EPA). In addition, the concentration of zinc ions was 500 kg/mg, 1500 kg/mg, and 3000 kg/mg, which caused an increase in compressive strength in the early period of age, and a decrease at a later age. An increase in the iron ion concentration caused an increase in the compressive strength at a later age, the effective retention percentages were (97, 93.5, 96 and 92) for iron, zinc, manganese and chromium ions, respectively, which exceeded 3000 mg/kg initially. The high effectiveness in holding and retaining metals within the matrix of solidification/stabilization at the particle size above 9.5 mm was found as well. The samples (Mn and Cr) with the low amount of cement in the mix treatment were not able to retain the required TCLP regulatory limits value, and the initial extraction pH 4.9. However, the final pH 9.5 is alkanet and stabilization effects of the cement matrix.
Źródło:
Journal of Ecological Engineering; 2019, 20, 3; 91-100
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Ultrasonic Vibration on the Solidification of 35CrMo Steel
Autorzy:
Zheng-Bing, X.
Yuan-Chun, H.
Powiązania:
https://bibliotekanauki.pl/articles/352200.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasonic vibration
solidification
segregation
defects
Opis:
The effect of ultrasonic vibration on the microstructure, elimination of casting defects and distribution of alloyed elements at macro-scale during solidification of 35CrMo steel has been investigated. Results show that ultrasonic treatment has a significant effect on the grain refinement, especially the fragmentation of the secondary dendritic arms of the studied steel. Density of the casting defects decreases and the alloyed elements are seen more even distribution at macro-scale with the introduction of ultrasonic vibration. Meanwhile, the ultrasonic vibration works more efficiently in the longitudinal direction than in the radial, and its efficiency declines with the distance from the radiator increasing.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 293-298
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solidification Front of Oriented Ledeburite
Autorzy:
Trepczyńska-Łent, M.
Olejnik, E.
Powiązania:
https://bibliotekanauki.pl/articles/381823.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
directional solidification
ledeburite
eutectic
solid interface
liquid interface
leading phase
krzepnięcie kierunkowe
ledeburyt
eutektyk
Opis:
Directional solidification of the Fe - 4,3 wt % C alloy was performed with the pulling rate equal to v=83 μm/s. Sample was frozen during solidification to reveal the shape of the solid/liquid interface. Structures eutectic pyramid and spherolitic eutectic were observed. The solidification front of ledeburite eutectic was revealed. The leading phase was identified and defined.
Źródło:
Archives of Foundry Engineering; 2016, 16, 1; 124-130
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Koncepcja stanowiska do badania procesu krzepnięcia w wilgotnych budowlanych materiałach porowatych
The conception of position to test of solidification process in wet building porous materials
Autorzy:
Partyka, J.
Lipnicki, Z.
Powiązania:
https://bibliotekanauki.pl/articles/372264.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
krzepnięcie
front krzepnięcia
porowaty materiał budowlany
solidification
solidification front
porous building materials
Opis:
W niniejszej pracy przedstawiono projekt koncepcyjny stanowiska badawczego do badania procesu krzepnięcia wilgotnych budowlanych materiałów porowatych. Planowany eksperyment polega na rejestracji frontu krzepnięcia w czasie, w zależności od warunków zewnętrznych. Idea pomiaru frontu krzepnięcia oparta jest na wykorzystaniu zmiany właściwości fizycznych wody w procesie krzepnięcia.
The test stand taken by the proposed project is to perform experimental studies measuring the solidification front in moist building porous materials. The objective of the proposed research is verification of theoretical experimental research conducted by the authors at the Department of Civil and Environmental Engineering University of Zielona Góra. Project research station is an original solution based on the original concept of the research. The experimental measurement of development of solidification front, especially in moist porous materials is a very difficult task. Therefore, the concept was difficult to measure observable solidification front seems to be interesting and worth implementing.
Źródło:
Zeszyty Naukowe. Inżynieria Środowiska / Uniwersytet Zielonogórski; 2014, 153 (33); 93-99
1895-7323
Pojawia się w:
Zeszyty Naukowe. Inżynieria Środowiska / Uniwersytet Zielonogórski
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Model for Solidification Zones Selection in the Large Ingots
Autorzy:
Wołczyński, W.
Kwapisiński, P.
Kania, B.
Wajda, W.
Skuza, W.
Bydałek, A. W.
Powiązania:
https://bibliotekanauki.pl/articles/379882.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
theory of crystallization
thermal gradient field
constrained solidification
unconstrained solidification
teoria krystalizacji
gradientowe pole temperatury
krzepnięcie ograniczone
Opis:
A vertical cut at the mid-depth of the 15-ton forging steel ingot has been performed by curtesy of the CELSA – Huta Ostrowiec plant. Some metallographic studies were able to reveal not only the chilled undersized grains under the ingot surface but columnar grains and large equiaxed grains as well. Additionally, the structural zone within which the competition between columnar and equiaxed structure formation was confirmed by metallography study, was also revealed. Therefore, it seemed justified to reproduce some of the observed structural zones by means of numerical calculation of the temperature field. The formation of the chilled grains zone is the result of unconstrained rapid solidification and was not subject of simulation. Contrary to the equiaxed structure formation, the columnar structure or columnar branched structure formation occurs under steep thermal gradient. Thus, the performed simulation is able to separate both discussed structural zones and indicate their localization along the ingot radius as well as their appearance in term of solidification time.
Źródło:
Archives of Foundry Engineering; 2015, 15, 4; 87-90
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
X-ray Diffraction Study of Directional Solidification Ledeburite
Autorzy:
Trepczyńska-Łent, M.
Szykowny, T.
Powiązania:
https://bibliotekanauki.pl/articles/379952.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
X-ray diffraction
ledeburite eutectic
directional solidification
dyfrakcja rentgenowska
ledeburyt
krzepnięcie kierunkowe
Opis:
Directionally solidified sample of Fe-Fe3C eutectic alloy were produced under an argon atmosphere in a vacuum Bridgman-type furnace to study the eutectic growth with v = 167 μm/s pulling rate and constant temperature gradient G = 33.5 K/mm. Since how the growth texture of eutectic cementite is related to its growth morphology remains unclear, the current study aims to examine this relationship. The technique such as X-ray diffraction, have been used for the crystallographic analysis of carbide particles in white cast irons.
Źródło:
Archives of Foundry Engineering; 2015, 15, 3; 71-76
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Al-Si-Re Alloys Cast by the Rapid Solidification Process
Stopy Al-Si-Re odlewane metodą rapid solidification
Autorzy:
Szymanek, M.
Augustyn, B.
Kapinos, D.
Żelechowski, J.
Bigaj, M.
Powiązania:
https://bibliotekanauki.pl/articles/356571.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aluminium alloy
rapid solidification
grain refinement
ultrafine structure
stop aluminium
szybka krystalizacja
rozdrobnienie ziarna
rozdrobnienie struktury
Opis:
The aim of the studies described in this article was to present the effect of rare earth elements on aluminium alloys produced by an unconventional casting technique. The article gives characteristics of the thin strip of Al-Si-RE alloy produced by Rapid Solidification (RS). The effect of rare earth elements on structure refinement, i.e. on the size of near-eutectic crystallites in an aluminium–silicon alloy, was discussed. To determine the size of crystallites, the Scherrer X-ray diffraction method was used. The results presented capture relationships showing the effect of variable casting parameters and chemical composition on microstructure of the examined alloys. Rapid Solidification applied to Al-Si alloys with the addition of mischmetal (Ce, La, Ne, Pr) refines their structure.
Celem badań opisanych w artykule było przedstawienie wpływu pierwiastków metali ziem rzadkich na stopy aluminium otrzymywane niekonwencjonalną metodą odlewniczą. W artykule scharakteryzowano cienką taśmę ze stopu Al-Si-RE wytworzoną metodą szybkiej krystalizacji (Rapid Solidification). Przedstawiono wpływ pierwiastków metali ziem rzadkich na rozdrobnienie struktury - wielkość krystalitów okołoeutektycznego stopu aluminium - krzem. Do oznaczenia wielkości krystalitów wykorzystano rentgenowską dyfrakcyjną metodę Scherrera. Zaprezentowane wyniki ujmują zależności zmiennych parametrów odlewania i składu chemicznego na mikrostrukturę badanych stopów. Zastosowanie szybkiej krystalizacji dla stopów Al-Si z dodatkiem miszmetalu (Ce, La, Ne, Pr) powoduje rozdrobnienie ich struktury.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 4; 3057-3062
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial perturbations in the solidification process due to mold delaminations
Zaburzenia przestrzenne procesów krzepnięcia wywołane delaminacjami na ściance formy
Autorzy:
Pauk, V.J.
Woźniak, M.
Powiązania:
https://bibliotekanauki.pl/articles/281242.pdf
Data publikacji:
1998
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
solidification
mold delamination
Opis:
The solidification process involving small periodical perturbations due to the system of mold delaminations is considered. Imperfections at the mold wall are modelled by non-ideal thermal contact conditions. It leads to the small perturbation in the solid-liquid interface and in the temperature distribution in the solid phase. With the help of approximate technique, known as the heat-balance integral method, the problem is reduced to the sequence of ordinary differential equations in amplitudes of the Fourier series of the solidification front. The shape of solid-liquid interfaces is shown.
W pracy rozpatruje się zagadnienie dwuwymiarowego niestacjonarnego przepływu ciepła w półprzestrzeni ze zmianami fazowymi. Uwzględniono zaburzenia przestrzenne wywołane delaminacjami pomiędzy falą stałą a ścianką formy. Imperfekcje mają rozkład periodyczny i powodują małe periodyczne zaburzenia zarówno w polu temperatury jak i w ruchomej powierzchni rozgraniczającej fazy stałą i ciekłą. W oparciu o przybliżoną metodę znaną jako metodę całek bilansu ciepła, zagadnienie nie sprowadza się do ciągu równań różniczkowych zwyczajnych dla makro-grubości krzepnącej warstwy oraz amplitud zaburzeń frontu krzepnięcia. Rozwiązania analityczne otrzymano pominąwszy kwadraty pewnych małych wielkości. Na wykresach przedstawiono zmiany zaburzeń w czasie dla różnych wartości wyjściowych parametrow.
Źródło:
Journal of Theoretical and Applied Mechanics; 1998, 2; 321-330
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solidification of Sludge from Waste Water Treatment
Zestalanie osadów z oczyszczania ścieków
Autorzy:
Korotenko, E.
Hendrych, J.
Masin, P.
Powiązania:
https://bibliotekanauki.pl/articles/318854.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
stabilizacja
zestalanie
szlam
odciek
stabilization
solidification
sludge
leachate
Opis:
This paper is aimed to the stabilization/solidification of sludge from wastewater treatment. Wastewater arised from illegal handling with waste galvanic sludge contacted by the silage waters. Treated sludge contained high amount of heavy metals and dissolved organic substances and inorganic salts. Solidificates were leached according to standardized method ČSN EN 12457-4 and assessed in accordance with Decree no. 294/2005 Coll. High content of dissolved organic carbon content (DOC) and total dissolved solids (TDS), which is expected with regard to the character and origin of analyzed/processed sludge, were critical indicators. Required legislative limits were met only if the ratio of the binder to the sludge was sufficiently large, namely for the series of untreated sludge (K0) and pre-treated sludge (K1, K2) this ratio was 80/20, for the sludge pre-treated by sludge filter press (N) 60/40. Heavy metals were stabilized with high efficiency were not critical in relation to the legislative limits. For the considered mixtures the costs were estimated.
W artykule przedstawiono wyniki badań nad stabilizacją (zestaleniem) osadów z oczyszczania ścieków. Ścieki pochodziły z nielegalnego zrzutu z galwanizerni. Poddany obróbce szlam zawierał duże ilości metali ciężkich i rozpuszczone substancje organiczne oraz sole nieorganiczne. Fazę stałą ługowano zgodnie ze znormalizowaną metodą ČSN EN 12457-4 i ocenione zgodnie z rozporządzeniem nr 294/2005 Coll. Wysoka zawartość rozpuszczonego węgla organicznego (DOC) i całkowitą ilością rozpuszczonej fazy stałej (TDS), które decydują o jakości osadu (szlamu). Limity określone w stosownym rozporządzeniu były spełnione tylko wtedy, gdy stosunek osadu do całkowitej objętości ścieków był wystarczająco duży, a mianowicie dla nieoczyszczonego szlamu (K0) i szlamu poddanego wstępnej obróbce (K1, K2) ten stosunek wynosił 80/20, dla szlamu poddanego wstępnej obróbce na prasie filtracyjnej (N) 60/40. Zawartość metali ciężkich ustabilizowała się na wysokim poziomie, wydajność nie przekraczała wartości krytycznych określonych w ustawie. Dla badanych osadów oszacowano koszty odwadniania i przeróbki.
Źródło:
Inżynieria Mineralna; 2018, R. 19, nr 1, 1; 103-110
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Fluid Flow and Solidification in Billet Caster Continuous Casting Mold with Electromagnetic Stirring
Autorzy:
Maurya, A.
Kumar Jha, P.
Powiązania:
https://bibliotekanauki.pl/articles/351082.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
continuous casting
mold
electromagnetic stirring
fluid flow
solidification
Opis:
Electromagnetic stirrer generates swirling fluid flow, boosts the mixing of molten steel near the solidification front and enhances the quality of the continuously cast products. In the present investigation, attention is paid towards studying the effect of in-mold electromagnetic stirring on fluid flow and solidification. A three-dimensional coupled mathematical model of solidification and magnetohydrodynamics has been established for billet caster mold. The alternating magnetic field is applied to the solidification model where fluid flow, heat transfer, and electromagnetic equations are solved simultaneously. It has been found that an increase in field frequency decreases the length of stirring and the liquid fraction of the steel at the center of the mold exit. Tangential velocity near the solidification front increases with the magnetic field frequency or flux density, due to which, a break in solidified shell near stirrer position is predicted whose width increases accordingly.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 413-424
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stabilization/Solidification of Tailing on Traditional Gold Mining in Kulon Progo Using Fly Ash
Autorzy:
Rachman, R. M.
Bahri, A. S.
Trihadiningrum, Y.
Powiązania:
https://bibliotekanauki.pl/articles/123406.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
mercury
fly ash
stabilization/solidification
tailings
Opis:
Traditional gold mining activity is one of the sources of mercury contamination. Total mercury concentration in tailing ponds in Kulon Progo ranged from 164.49 mg/kg to 383.21 mg/kg, which exceeded the quality standard values set by the government of Indonesia No. 101 of 2014, which is 75 mg/kg. One method that can be applied is stabilization/solidification (S/S). This study aims to determine the optimum composition of the tailing mixture with fly ash in S/S process. The variations of fly ash composition with tailing are 100: 0, 90: 10, 80: 20, 70: 30, 60: 40, 50: 50, 40: 60, 30: 70, 20: 80 and 10: 90. The results of the study found that the optimum composition of fly ash: tailings was 10: 90, with compression test of 74 ton/m2 and TCLP test was 0.0069 mg/L. The obtained compression test results were in accordance with US EPA Standard quality of 35 ton/m2. TCLP test results meet the standard of Indonesian Government Regulation no. 101 of 2014, amounting to 0.05 mg/L.
Źródło:
Journal of Ecological Engineering; 2018, 19, 3; 178-184
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Directional Solidification of AlSi Alloys with Fe Intermetallic Phases
Autorzy:
Mikołajczak, P.
Ratke, L.
Powiązania:
https://bibliotekanauki.pl/articles/379990.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
directional solidification
aluminum alloys
calibration
intermetallic phases
krzepnięcie kierunkowe
stopy aluminium
kalibracja
fazy międzymetaliczne
Opis:
Directional solidification technique is an important research instrument to study solidification of metals and alloys. In the paper the model [6,7,8] of directional solidification in special Artemis-3 facility was presented. The current work aimed to propose the ease and efficient way in calibrating the facility. The introduced M coefficient allowed effective calibration and implementation of defined thermal conditions. The specimens of AlSi alloys with Fe-rich intermetallics and especially deleterious β-Al5FeSi were processed by controlled solidification velocity, temperature gradient and cooling rate.
Źródło:
Archives of Foundry Engineering; 2014, 14, 1; 75-78
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of two-stage solidification: Part I model development
Autorzy:
Wodo, O.
Gawrońska, E.
Powiązania:
https://bibliotekanauki.pl/articles/380434.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
automat komórkowy
krzepnięcie
modelowanie mikrostrukturalne
struktura eutektyczna
cellular automata
solidification
microstructure modeling
dendritic structure
eutectic structure
Opis:
The paper presents a new numerical model of solidification processes in hypoeutectic alloys. The model combines stochastic elements, such as e.g. random nucleation sites and orientation of dendritic grains, as well as deterministic methods e.g. to compute velocity of dendritic tips and eutectic grains. The model can be used to determine the temperature and the size of structure constituents (of both, the primary solid phase and eutectics) and the arrangement of individual dendritic and eutectic grains in the consecutive stages of solidification. Two eutectic transformation modes, typical to modified and unmodified hypoeutectic alloys, have been included in the model. To achieve this, cellular automata and Voronoi diagrams have been utilized.
Źródło:
Archives of Foundry Engineering; 2012, 12, 4; 151-156
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Contact Gap in Directional Solidification of AlSiFe Alloys
Autorzy:
Mikołajczak, P.
Ratke, L.
Powiązania:
https://bibliotekanauki.pl/articles/381310.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
directional solidification
aluminium alloys
calibration
intermetallic phases
krzepnięcie kierunkowe
stop aluminium
kalibracja
faza międzymetaliczna
Opis:
One of the methods to study solidification of alloys and metals is directional solidification. In the paper the effect of the contact gap between the analyzed specimen and the bottom heater was analysed. The occurring contact gap caused the increase in planned solidification velocity. For the facility calibration the methodology with M coefficient was applied. The experiments revealed efficient values of M and allowed to conduct efficiently the directional solidification of AlSiFe alloys in wide range of growth rates. The effect of the contact gap seems to be random phenomena and most difficult factor influencing precisely planned directional solidification.
Źródło:
Archives of Foundry Engineering; 2014, 14, 3 spec.; 41-44
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Model of SiC Particle Interaction with Solidification Front in AZ91/(SiCp) Composite
Autorzy:
Żak, P. L.
Kalisz, D.
Rączkowski, G.
Powiązania:
https://bibliotekanauki.pl/articles/355818.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AZ91/SiCp composite
solidification front
modeling
Opis:
Presented work focused on the movement of SiC particles in the vicinity of the solidification front in AZ91/(SiC)p composite. Authors describe the mathematical model that governs this phenomenon. On the base of following numerical model own computer program was prepared. The behavior of a particle moving parallel to the solidification front was analyzed. Three variants of local velocity gradient of liquid metallic phase were analyzed for a particle of radius 10, 50 and 100 μm. At a bigger velocity gradient the SiC particle was observed to go down quicker and to move towards the solidification front. This effect was stronger for SiC particles, which had a bigger radius, i.e. 100 and 50 μm.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 3; 1625-1628
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Leading Phase in the Directionally Solidifying Fe – 4.25%C Eutectic Alloy
Autorzy:
Trepczyńska-Łent, M.
Powiązania:
https://bibliotekanauki.pl/articles/380702.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
directional solidification
eutectic alloy Fe-C
solidification front
leading phase
krzepnięcie kierunkowe
stop eutektyczny
front krzepnięcia
Opis:
In order to determine the leading phase of the Fe - 4.25% C eutectic alloy, the method of directional crystallization, which allows to study the character of the solid / liquid growth front, was used. Examined eutectic was directionally solidified with a constant temperature gradient of G = 33,5 K/mm and growth rate of v = 125 μm/s (450 mm/h). The Bridgman technique was used for the solidification process. The sample was grown by pulling it downwards up to 30 mm in length. The alloy quenched by rapid pulling down into the Ga-In-Sn liquid metal. The sample was examined on the longitudinal section using a light microscope and scanning electron microscope. The shape of the solid/liquid interface and particularly the leading phase protrusion were revealed. The formation of the concave – convex interface has been identified in the quasi-regular eutectic growth arrested by quenching. The cementite phase was determined to be a leading phase. The total protrusion d is marked in the adequate figure.
Źródło:
Archives of Foundry Engineering; 2019, 4; 113-116
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
XRD and EBSD Measurements of Directional Solidification Fe-C Eutectic Alloy
Autorzy:
Trepczyńska-Łent, M.
Powiązania:
https://bibliotekanauki.pl/articles/382146.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
X-ray diffraction
EBSD technique
carbide eutectic
directional solidification
dyfrakcja rentgenowska
dyfrakcja elektronów wstecznie rozproszonych
krzepnięcie kierunkowe
Opis:
In a vacuum Bridgman-type furnace, under an argon atmosphere, directionally solidified sample of Fe-C alloy was produced. The pulling rate was v = 83 μm/s (300 mm/h) and constant temperature gradient G = 33,5 K/mm. The microstructure of the sample was examined on the longitudinal section using an Optical Microscope and Scanning Electron Microscope. The X-ray diffraction and electron backscatter diffraction technique (EBSD) have been used for the crystallographic analysis of carbide particles in carbide eutectic. The X-ray diffraction was made parallel and perpendicular to the axis of the goniometer. The EBSD shows the existence of iron carbide Fe3C with orthorhombic and hexagonal structure. Rapid solidification may cause a deformation of the lattice plane which is indicated by different values of the lattice parameters. Such deformation could also be the result of directional solidification. Not all of the peaks in X–ray diffractograms were identified. They may come from other iron carbides. These unrecognized peaks may also be a result of the residual impurity of alloy.
Źródło:
Archives of Foundry Engineering; 2016, 16, 4; 169-174
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interaction of Non-Metallic Inclusion Particles with Advancing Solidification Front
Oddziaływanie cząstek wydzieleń niemetalicznych z postępującym frontem krzepnięcia
Autorzy:
Kalisz, D.
Powiązania:
https://bibliotekanauki.pl/articles/354360.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
solidification front
non-metallic inclusions
forces
front krzepnięcia
wydzielenie niemetaliczne
siła
Opis:
This work deals the phenomenon interaction of crystallization front on the particles of non-metallic precipitates. The behavior of a single particle in the vicinity of horizontal and vertical front was analyzed. The forces acting on the particle were characterized and the equilibrium condition formulated, from which the critical velocity of front may be deduced. The calculation results were illustrated in the form of graphs.
Praca zajmuje się zjawiskiem oddziały wania przemieszczającego frontu krystalizacji na cząstki wydzieleń niemetalicznych. Analizowano zachowanie pojedynczej cząstki wydzielenia w pobliżu poziomego i pionowego frontu. Scharakteryzowano siły działające na cząstkę w pobliżu frontu i sformułowano warunek równowagi, z którego wynika szybkość krytyczna frontu. Wyniki obliczeń zilustrowano w postaci wykresów.
Źródło:
Archives of Metallurgy and Materials; 2014, 59, 2; 493-500
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Study of the Tensile Strength of AlSi21CuNiMg Silumin in the Final Stage of Solidification and the Initial Stage of Cooling
Autorzy:
Romankiewicz, Remigiusz
Powiązania:
https://bibliotekanauki.pl/articles/106921.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
silumin
solidification
modification
tensile strength
Opis:
The paper presents the results of tensile strength tests of AlSi21CuNiMg silumin made on a test stand. Silumin was under examination in an unmodified state and after modification with AlCu19P1.4 master alloy in quantity of 0.2% in relation to the mass of the alloy. Using a scanning microscope, the surface fractures obtained from tensile tests were tested. The structure and profiles of fractures were examined using an optical microscope. Modification of the tested silumin resulted in a favorable fragmentation and regular distribution of the crystals of the primary silicon in the alloy structure, which led to an almost twofold increase in the strength of the silumin samples at the final solidification stage from 3.5 to 6.6 MPa. As a result of these changes, the resistance of silumin to hot cracks should increase, which is of great importance when casting hypereutectic silumin in a metal mould that strongly inhibits the shrinkage of the castings.
Źródło:
Journal of Casting & Materials Engineering; 2019, 3, 3; 57-61
2543-9901
Pojawia się w:
Journal of Casting & Materials Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of two-stage solidification: Part II computational verification of the model
Autorzy:
Wodo, O.
Gawrońska, E.
Powiązania:
https://bibliotekanauki.pl/articles/380341.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cellular automata
solidification
microstructure modeling
dendritic structure
eutectic structure
automat komórkowy
krzepnięcie
modelowanie mikrostrukturalne
struktura eutektyczna
Opis:
In Part I of this article, two-stage solidification model was presented. In this part we use our model to simulate solidification of the Al 7% Si alloy for two cooling rates - 2 deg/s and - 20 deg/s. Simulations have been performed for two eutectic transformation modes, typical for modified and unmodified alloys. Obtained cooling curves are qualitatively consistent with the typical cooling curves for modified and unmodified alloys. Moreover, evolution of cooling-curve characteristics is compared with the analytical model and found to be in close agreement.
Źródło:
Archives of Foundry Engineering; 2013, 13, 1; 125-130
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical modeling of pure metal solidification using the one domain approach
Autorzy:
Szopa, R.
Powiązania:
https://bibliotekanauki.pl/articles/973637.pdf
Data publikacji:
2015
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
solidification of metal
Stefan problem
artificial mushy zone
numerical methods
krzepnięcie metalu
problem Stefana
sztuczna strefa dwufazowa
metody numeryczne
Opis:
Numerical modeling of pure metal solidification on the basis of the well-known Stefan model is rather difficult. The knowledge of temporary solidification front position and the local values of the solidification rate in the normal direction for time t are necessary in order to determine the new position of moving boundary for time t + ∆t. The problem is especially complicated for 2D and 3D tasks. The concept greatly simplifying the modeling of solidification process boils down to the introduction of the artificial region corresponding to the mushy zone sub-domain. For this region the substitute thermal capacity is defined and the mathematical model corresponds to the one domain approach. The artificial mushy zone appears owing to conventional enlargement of solidification point on a certain interval of temperature ∆T. The basic goal of the paper is the numerical analysis of the influence of the interval ∆T on the numerical solution simulating the thermal processes in the domain of the solidifying metal.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2015, 14, 3; 121-126
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of solidification behaviour and mechanical properties of arc stud welded AISI 316L stainless steel
Autorzy:
Abass, M. H.
Alali, M. S.
Abbas, W. S.
Shehab, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/367964.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
arc stud welding
AISI 316L stainless steel
solidification mode
solidification cracking
second phase
spawanie łukowe
stal nierdzewna AISI 316L
model krzepnięcia
druga faza
Opis:
Purpose: This paper aims to investigate the impact of arc stud welding (ASW) process parameters on the microstructure and mechanical properties of AISI 316L stainless steel stud/plate joint. Design/methodology/approach: The weld performed using ASW machine. The influence of welding current and time on solidification mode and microstructure of the fusion zone (FZ) was investigated using optical microscope and scanning electron microscope (SEM). Microhardness and torque strength tests were utilised to evaluate the mechanical properties of the welding joint. Findings: The results showed that different solidification modes and microstructure were developed in the FZ. At 400 and 600 A welding currents with 0.2 s welding time, FZ microstructure characterised with single phase austenite or austenite as a primary phase. While with 800 A and 0.2 s, the microstructure consisted of ferrite as a primary phase. Highest hardness and maximum torque strength were recorded with 800 A. Solidification cracking was detected in the FZ at fully austenitic microstructure region. Research limitations/implications: The main challenge in this work was how to avoid the arc blow phenomenon, which is necessary to generate above 300 A. The formation of arc blow can affect negatively on mechanical and metallurgical properties of the weld. Practical implications: ASW of austenitic stainless steel are used in multiple industrial sectors such as heat exchangers, boilers, furnace, exhaust of nuclear power plant. Thus, controlling of solidification modes plays an important role in enhancing weld properties. Originality/value: Study the influence of welding current and time of ASW process on solidification modes, microstructure and mechanical properties of AISI 316 austenitic stainless steel stud/plate joint.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2019, 97, 1; 5-14
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Solidification Rate on High-tin Bronze Microstructure
Autorzy:
Bartocha, D.
Baron, C.
Suchoń, J.
Powiązania:
https://bibliotekanauki.pl/articles/380563.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high-tin bronze
solidification rate
microstructure
bell’s tone
brąz wysokocynowy
szybkość krzepnięcia
mikrostruktura
dzwon
Opis:
The most important feature of bells is their sound. Their clarity and beauty depend, first of all, on the bell’s geometry - particularly the shape of its profile and the mechanical properties of alloy. Bells are the castings that work by emitting sound in as-cast state. Therefore all features that are created during melting, pouring, solidification and cooling processes will influence the bell's sound. The mechanical properties of bronze depend on the quality of alloy and microstructure which is created during solidification and depend on its kinetics. Hence, if the solidification parameters influence the alloy’s properties, how could they influence the frequencies of bell`s tone? Taking into account alterable thickness of bell's wall and differences in microstructure, the alloy's properties in bell could be important. In the article authors present the investigations conducted to determine the influence of cooling kinetics on microstructure of bronze with 20 weight % tin contents.
Źródło:
Archives of Foundry Engineering; 2019, 1; 89-97
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of solidification of a casting taking into account fluid flow and heat transfer phenomena. The axisymmetrical problem
Autorzy:
Parkitny, R.
Sowa, L.
Powiązania:
https://bibliotekanauki.pl/articles/281858.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
solidification
molten metal flow
mould filling
mathematical modelling
Opis:
In the paper, a mathematical and a numerical model of solidification of a cylindrical shaped casting, which takes into account the process of filling the mould cavity with the molten metal, has been proposed. The feeding of the casting by a riser head during solidification has also been taken into cansideration. Velocity fields were obtained by solving the Navier-Stokes equations and the continuity equation, while thermal fields were obtained by solving the conduction equation containing the convection term. The changes in the thermophysical parameters, with respect to temperature, were taken into consideration. The problem was solved by the finite element method.
Symulacja numeryczna krzepnięcia odlewu z uwzględnieniem zjawisk cieplno-przepływowych. Zadanie osiowo-symetryczne. W pracy sformułowano model matematyczny i numeryczny procesu krzepnięcia odlewu o kształcie cylindrycznym z uwzględnieniem procesu wypełniania wnęki formy ciekłym metalem i zasilania odlewu przez nadlew podczas jego krzepnięcia. Uwzględniono wzajemną zależność zjawisk cieplnych i dynamicznych. Pola prędkości otrzymano z równań Naviera-Stokesa i równania ciągłości, natomiast pola temperatury z rozwiązania równania przewodzenia ciepła z członem konwekcyjnym. Uwzględniano zmianę parametrów termofizycznych w funkcji temperatury. Postawione zadanie rozwiązano metodą elementów skończonych.
Źródło:
Journal of Theoretical and Applied Mechanics; 2001, 39, 4; 909-921
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sharp Interface Numerical Modeling of Solidification Process of Pure Metal
Sposób modelowania numerycznego procesu krzepnięcia z ostrym frontem
Autorzy:
Skrzypczak, T.
Powiązania:
https://bibliotekanauki.pl/articles/356217.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Pure Metal
Stefan problem
Sharp Interface
solidification
finite element method
level set method
Opis:
The paper is focused on the study of the solidification process of pure metals, in which the solidification front is smooth. It has the shape of a surface separating liquid from solid in three dimensional space or a curve in 2D. The location and topology of moving interface change over time and its velocity depends on the values of heat fluxes on the solid and liquid side of it. Such a formulation belongs to a group called Stefan problems. A mathematical model of the Stefan problem is based on differential equations of heat conduction and interface motion. This system of equations is supplemented by appropriate initial and boundary conditions as well as the continuity conditions at the solidification interface. The solution involves the determination of temporary temperature field and interface position. Typically, it is impossible to obtain the exact solution of such problem. This paper presents a mathematical model for the two-dimensional problem. The equation of heat conduction is supplemented with Dirichlet and Neumann boundary conditions. Interface motion is described by the level set equation which solution is sought in the form of temporary distribution of the signed distance function. Zero level of the distance field coincides with the position of the front. Values of the signed distance function obtained from the level set equation require systematic reinitialization. Numerical model of the process based on the finite element method (FEM) is also presented. FEM equations are derived and discussed. The explicit time integration scheme is proposed. It helps to avoid solving the system of equations during each time step. The reinitialization procedure of the signed distance function is described in detail. Examples of numerical analysis of the solidification process of pure copper within the complex geometry are presented. Results obtained from the use of constant material properties are compared with those obtained from the use of temperature dependent properties.
W pracy skupiono się na badaniu procesu krzepnięcia czystych metali, podczas którego front krzepnięcia pozostaje płaski. W przypadku trójwymiarowym jest on powierzchnia oddzielająca ciecz od ciała stałego, w przypadku dwuwymiarowym ma postać krzywej. Położenie i topologia frontu krzepnięcia zmienia się w czasie, a prędkość przemieszczania zależy od różnicy wartości strumieni cieplnych po stronie ciała stałego i cieczy. Takie sformułowanie klasyfikuje opisywane zjawisko w grupie tzw. zagadnień Stefana. Model matematyczny tego procesu stanowią równania różniczkowe przewodnictwa ciepła oraz ruchu powierzchni międzyfazowej. Układ ten uzupełniają odpowiednie warunki brzegowe, początkowe oraz warunki ciągłości na froncie. Jego rozwiązanie polega na wyznaczeniu chwilowych pól temperatury oraz położenia frontu. Najczęściej nie da się uzyskać rozwiązania tak sformułowanego problemu w sposób dokładny. W pracy zaprezentowano model matematyczny zagadnienia dla przypadku płaskiego. Równanie różniczkowe przewodnictwa ciepła uzupełniono warunkami brzegowymi Dirichleta oraz Neumanna. Ruch interfejsu międzyfazowego opisano tzw. równaniem poziomic (ang. level set equation), którego rozwiązania poszukiwano w postaci chwilowego rozkładu funkcji dystansu. Izolinia zerowa tego rozkładu pokrywa się z położeniem frontu. Otrzymane wartości funkcji dystansu wymagają systematycznej reinicjalizacji. Przedstawiono również model numeryczny procesu bazujący na metodzie elementów skończonych. Opisano schemat postępowania prowadzący do otrzymania dyskretnych równań MES. Wykorzystano jawny schemat całkowania po czasie, co pozwoliło uniknąć konieczności rozwiazywania układu równań zarówno w przypadku równania przewodnictwa ciepła jak i równania poziomic. Szczegółowo opisano metodę reinicjalizowania funkcji dystansu. Zaprezentowano przykłady analizy numerycznej procesu krzepnięcia czystej miedzi w obszarze o złożonej geometrii. Porównano wyniki otrzymane dla stałych własności materiałowych z wynikami uzyskanymi z wykorzystaniem własności zależnych od temperatury.
Źródło:
Archives of Metallurgy and Materials; 2012, 57, 4; 1189-1199
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Calculations of the Cast Solidification with the Complex Shape Including the Movement of the Liquid Phase
Autorzy:
Gawrońska, E.
Dyja, R.
Powiązania:
https://bibliotekanauki.pl/articles/379903.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
solidification
Navier-Stokes
streamline upwind Petrov-Galerkin
pressure stabilized Petrov-Galerkin
Opis:
The paper presents the results of the computer simulations of solidification with consideration of the liquid phase movement. Simulations were conducted in a real, complex cast. There is a multi-stage resolution to the problem of convection in solidification simulations. The most important resolution concerns the development of the numerical model with the momentum and continuity equations, as well as conditions which are determined by the convection. Simulations were carried out with the use of our authorial software based on stabilized finite elements method (Petroy-Galerkin). In order to solve Navier-Stokes equation (with the convection element), Boussinesq’s approximation were used. Finite Elements Method (FEM) was responsible for the solidification. FEM is close to the heat conduction equation solution (with the internal heat source responsible for the heat released during phase transformation). Convection causes movement in the liquid phase in the solidifying cast and can significantly influence the process of heat transfer from the cast. It may change the distribution of the defects. Results of this article make it possible to assess the conditions in which the influence of the convection on solidification is significant.
Źródło:
Archives of Foundry Engineering; 2018, 18, 3; 65-70
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stabilization/Solidification of Waste Containing Heavy Metals and Hydrocarbons Using OPC and Land Trass Cement
Autorzy:
Masrullita, -
Burhan, R. Y. P.
Trihadiningrum, Y.
Powiązania:
https://bibliotekanauki.pl/articles/952442.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
trass soil
heavy metal
ordinary Portland cement
OPC
stabilization/solidification
Opis:
The stabilization/solidification process (S/S) is one of the alternative methods of treating B3 waste, especially heavy metal. The S/S uses cement as the solidification agent. The cement will bind heavy metal pollutants in a monolithic mass with a sturdy structure, thus inhibiting its movement. The presence of hydrocarbons affects the S/S strength. Therefore, it is necessary to add pozzolan material which can absorb hydrocarbon constituting the cement blocking component of pozzolan cement, i.e. Ordinary Portland Cement (OPC) combined with trass soil. This study aims to determine the maximum content of organic materials in the form of hydrocarbons can stabilize/solidify heavy metals contained in wastes containing hydrocarbons. This research is conducted in two steps. Stage I aims to obtain the optimum composition of the mixture. On the other hand, stage II is to determine the maximum content of hydrocarbons in percent weight that can stabilize/solidify organic wastes containing heavy metals – Cu, Cr, and Pb in artificial wastes. The composition of OPC and trass soil was varied at a ratio of 100: 0, 5:25, 50:50, 25:75 and 0: 100. The hydrocarbons used in step II were paraffin, added to the optimum composition of OPC and trass soil with a proportion of 2.5%, 5%, 5% and 10%. The S/S product quality test was performed, involving: compressive strength test, Toxicity Characteristic Leaching Procedure (TCLP) and paint filter test. Strength test was conducted using a compressive strength testing apparatus Toasters Universal Testing Machine Type RAT-200, MFG No. 20380 CAP 200 tf. TCLP test under US-EPA (method 1311). The method of analysis pertaining to heavy metal concentrations involved a colorimetric method for Cr (VI), neocuproine for Cu, and dithizone for Pb. The paint test refers to the US EPA 9095B method. The results showed that the optimum composition of OPC mixture: trass soil was 50:50, which is the composition used in stage II. The results of compressive strength test were 2770 tons/m2. The TCLP test results for heavy metals Cu and Pb with hydrocarbon addition on Cu 10% and Pb 2.5% reached 0.076 and 0.076 mg/L, respectively. The result of the paint filter test indicates that there is no remaining free fluid.
Źródło:
Journal of Ecological Engineering; 2018, 19, 6; 88-96
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical model of solidification of the axisymmetric casting while taking into account its shrinkage
Autorzy:
Sowa, L.
Powiązania:
https://bibliotekanauki.pl/articles/122268.pdf
Data publikacji:
2014
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
mathematical modelling
solidification
shrinkage cavity
molten metal flow
modelowanie matematyczne
krzepnięcie
jama skurczowa
przepływ ciekłego metalu
Opis:
In this paper, the mathematical and numerical model of the solidification of a cylindrical shaped casting, while taking into account the process of the mould cavity filling with molten metal, has been proposed. The feeding of the casting by a riser head during solidification and the formation of shrinkage cavity has also been taken into consideration. The shape and depth of the shrinkage cavity distribution was estimated. One aim of the paper is to obtain a casting without shrinkage defects. Velocity fields were obtained by solving the Navier-Stokes equations and the continuity equation, while the thermal fields were obtained by solving the conduction equation containing the convection term. The changes in the thermophysical parameters, with respect to temperature, were taken into account. The problem was solved by the finite element method.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2014, 13, 4; 123-130
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Production of Material with Ultrafine Grain Structure in Al-Zn Alloy in the Process of Rapid Solidification
Autorzy:
Szymanek, M.
Augustyn, B.
Kapinos, D.
Boczkal, S.
Nowak, J.
Powiązania:
https://bibliotekanauki.pl/articles/381375.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
innovative foundry technologies
innovative foundry materials
aluminium alloys
solidification process
Rapid Solidification
innowacyjne technologie odlewnicze
innowacyjne materiały w odlewnictwie
stopy aluminium
krzepnięcie
szybkie krzepnięcie
Opis:
In the aluminium alloy family, Al-Zn materials with non-standard chemical composition containing Mg and Cu are a new group of alloys, mainly owing to their high strength properties. Proper choice of alloying elements, and of the method of molten metal treatment and casting enable further shaping of the properties. One of the modern methods to produce materials with submicron structure is a method of Rapid Solidification. The ribbon cast in a melt spinning device is an intermediate product for further plastic working. Using the technique of Rapid Solidification it is not possible to directly produce a solid structural material of the required shape and length. Therefore, the ribbon of an ultrafine grain or nanometric structure must be subjected to the operations of fragmentation, compaction, consolidation and hot extrusion. In this article the authors focussed their attention on the technological aspect of the above mentioned process and described successive stages of the fabrication of an AlZn9Mg2.5Cu1.8 alloy of ultrafinegra in structure designated for further plastic working, which enables making extruded rods or elements shaped by the die forging technology. Studies described in the article were performed under variable parameters determined experimentally in the course of the alloy manufacturing process, including casting by RS and subsequnt fragmentation.
Źródło:
Archives of Foundry Engineering; 2014, 14, 2; 57-62
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Process Parameters on Exudation Thickness in Continuous Unidirectional Solidification Tin Bronze Alloy
Autorzy:
Jihui, Luo
Fang, He
Powiązania:
https://bibliotekanauki.pl/articles/382552.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
unidirectional solidification
Tin bronze alloy
orthogonal experiment
exudation
krzepnięcie jednokierunkowe
stop cynowo-brązowy
eksperyment ortogonalny
wysięki
Opis:
The exudation layer seriously affects the properties and the surface finish of the tin bronze alloy. The effective control of the exudation thickness is important measure for improving the properties of the alloy. In order to study the influence of process parameters on the thickness of exudate layer, the tin bronze alloy was prepared by continuous unidirectional solidification technology at different process parameters. The microstructure of the continuous unidirectional solidification tin bronze alloy was analyzed. The effect of process parameters on microstructure and chemical compositions was studied by orthogonal experiment. The results show that there exists an exudation layer on the surface of the continuous unidirectional solidification tin bronze alloy, and the exudation is mainly composed of a tin-rich precipitated phase. It indicates that the continuous casting speed is the main factor affecting the thickness of exudation layer, followed by mold temperature, melt temperature, cooling water temperature and cooling distance.
Źródło:
Archives of Foundry Engineering; 2019, 2; 97-100
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reconstruction of the boundary condition in the problem of the binary alloy solidification
Odtworzenie warunku brzegowego w zagadnieniu krzepnięcia stopu dwuskładnikowego
Autorzy:
Słota, D.
Powiązania:
https://bibliotekanauki.pl/articles/351110.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
krzepnięcie
zagadnienie odwrotne
stop dwuskładnikowy
solidification
inverse problems
binary alloys
macrosegregation
Opis:
The solution of the inverse problem involving the designation of the boundary condition in the problem of the binary alloy solidification for known temperature measurements at a selected point of the cast is presented. In the discussed model, the temperature distribution is described by means of the Stefan problem with varying in time temperature corresponding to the beginning of solidification and depending on the concentration of the alloy component. Whereas to describe the concentration, the Scheil model was used.
W pracy przedstawiono rozwiązanie zagadnienia odwrotnego polegającego na określeniu warunku brzegowego w zagadnieniu krzepnięcia stopu dwuskładnikowego, gdy znane są pomiary temperatury w wybranym punkcie odlewu. W rozważanym modelu rozkład temperatury opisany został zagadnieniem Stefana ze zmienną w czasie temperaturą odpowiadającą początkowi procesu krzepnięcia, zależną od stężenia składnika stopowego. Do opisu stężenia wykorzystano model Scheila.
Źródło:
Archives of Metallurgy and Materials; 2011, 56, 2; 278-285
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Verification of the Cast Iron Solidification Model
Autorzy:
Mendakiewicz, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/2174627.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
foundry industry
application of information technology
solidification process
numerical techniques
thermal analysis
derivative analysis
przemysł odlewniczy
zastosowanie technologii informatycznych
krzepnięcie
techniki numeryczne
analiza termiczna
Opis:
The article concerns the experimental verification of the numerical model simulating the solidification and cooling processes proceeding in the domain of cast iron casting. The approximate course of the function describing the evolution of latent heat and the value of substitute specific heat resulting from its course were obtained using the thermal and derivative analysis (TDA) method The TDA was also used to measure the cooling curves at the distinguished points of the casting. The results obtained in this way were compared with the calculated cooling curves at the same points. At the stage of numerical computations, the explicit scheme of the finite difference method was applied. The agreement between the measured and calculated cooling curves is fully satisfactory.
Źródło:
Archives of Foundry Engineering; 2022, 22, 3; 91--94
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Producing Ultrafine Grain Structure in AZ91 Magnesium Alloy Cast by Rapid Solidification
Wytwarzanie materiału o ultradrobnoziarnistej strukturze ze stopu magnezu AZ91 odlewanego w procesie rapid solidification
Autorzy:
Szymanek, M.
Augustyn, B.
Kapinos, D.
Boczkal, S.
Nowak, J.
Powiązania:
https://bibliotekanauki.pl/articles/353516.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnesium alloy
rapid solidification
plastic consolidation
hot extrusion
extrusion die profile
stopy magnezu
szybkie krzepnięcie
konsolidacja plastyczna
wytłaczanie na gorąco
Opis:
The paper presents the technological aspect of the process of casting, crushing and plastic consolidation of semi-finished products from magnesium alloy. The aim of this study was to produce by the rapid solidification process a magnesium alloy from the MgAl9Zn1 family in the form of ribbons with ultrafine grain structure. The material cast in the melt spinning device was next crushed and subjected to the operation of cold consolidation and hot extrusion. The paper presents different stages of the process, including initial characterisation of the obtained material.
W artykule przedstawiono aspekt technologiczny procesu odlewania, rozdrabniania i konsolidacji plastycznej otrzymywa- nych półwyrobów ze stopu magnezu. Celem pracy było wytworzenie metodą szybkiej krystalizacji stopu magnezu z układu MgAlOZn1, o ultradrobnoziarnistej strukturze w postaci taśmy. Materiał odlany na stanowisku melt spinning w kolejnym etapie został rozdrobniony i poddany procesowi konsolidacji na zimno i wyciskaniu na gorąco. W artykule zostały przedstawione poszczególne etapy procesu wraz z wstępną charakteryzacją otrzymywanego materiału.
Źródło:
Archives of Metallurgy and Materials; 2014, 59, 1; 317-321
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of Dendritic Structure Evolution During Solidification of Al-Cu Alloy
Autorzy:
Zyska, A.
Boroń, K.
Kordas, P.
Powiązania:
https://bibliotekanauki.pl/articles/382278.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
alloy solidification
cellular automata
AlCu alloy
structure modeling
krzepnięcie stopu
automat komórkowy
stop AlCu
modelowanie struktury
Opis:
The paper presents the cellular automaton (CA) model for tracking the development of dendritic structure in non-equilibrium solidification conditions of binary alloy. Thermal, diffusion and surface phenomena have been included in the mathematical description of solidification. The methodology for calculating growth velocity of the liquid-solid interface based on solute balance, considering the distribution of the alloy component in the neighborhood of moving interface has been proposed. The influence of solidification front curvature on the equilibrium temperature was determined by applying the Gibbs Thomson approach. Solute and heat transfer equations were solved using the finite difference method assuming periodic boundary conditions and Newton cooling boundary condition at the edges of the system. The solutal field in the calculation domain was obtained separately for solid and liquid phase. Numerical simulations were carried out for the Al-4 wt.% Cu alloy at two cooling rates 15 K/s and 50 K/s. Microstructure images generated on the basis of calculations were compared with actual structures of castings. It was found that the results of the calculations are agreement in qualitative terms with the results of experimental research. The developed model can reproduce many morphological features of the dendritic structure and in particular: generating dendritic front and primary arms, creating, extension and coarsening of secondary branches, interface inhibition, branch fusion, considering the coupled motion and growth interaction of crystals.
Źródło:
Archives of Foundry Engineering; 2018, 18, 4; 87-92
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient solidification of Pb2+ by activated tungsten tailings and cement
Autorzy:
Cheng, Hao
Kuang, Jingzhong
Zhu, Luping
Yuan, Weiquan
Huang, Zheyu
Yang, Yiqiang
Powiązania:
https://bibliotekanauki.pl/articles/24085840.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
tungsten tailings
activation
Pb2+
Solidification
C-S-H gel
Opis:
The preparation of cementing admixture from tailings and co-solidification of Pb2+ with cement is a green way to realize the resource utilization of tailings and treatment of the lead-containing wastewater. In this paper, the tungsten tailings were activated in different ways, and the mechanical properties of the tungsten tailings-cement solidified body with different activation systems and the solidification behavior of Pb2+ were studied. The phase and microstructure of the hydrated product were characterized by XRD, FT-IR, SEM and EDS. The results showed that the curing effect of Pb2+ was obviously different of different activation systems, and the curing effect of the solidified body of the ternary composite activation system (TCAS) was the best, second only to the pure cement system (PCS). Different activation methods have a significant impact on the mechanical properties of the solidified body. With the increase of the Pb2+ content, the compressive strength of the solidified body gradually decreased, the Pb2+ leaching concentration gradually increased; with the extension of the curing age, the compressive strength gradually increased, and the Pb2+ leaching concentration gradually decreased. In particular, the compressive strength of the 28d solidified body was 31.43 MPa and the leaching concentration of Pb2+ was only 0.38 mg/L when the Pb2+ content was 5%. The phase, microstructure and EDS results of the hydration products showed that Pb2+ was mainly solidified in the C-S-H gel.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 162618
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of a binary fluid solidification model using semi-analitycal solution of 1D heat diffusion equation
Autorzy:
Wacławczyk, T.
Schäfer, M.
Powiązania:
https://bibliotekanauki.pl/articles/952683.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heat diffusion
semi-analytical solution
numerical methods
binary fluid solidification
dyfuzja ciepła
metody numeryczne
Opis:
The aim of the present work is to verify a numerical implementation of a binary fluid, heat conduction dominated solidification model with a novel semi-analytical solution to the heat diffusion equation. The semi-analytical solution put forward by Chakaraborty and Dutta (2002) is extended by taking into account variable in the mushy region solid/liquid mixture heat conduction coefficient. Subsequently, the range in which the extended semi-analytical solution can be used to verify numerical solutions is investigated and determined. It has been found that linearization introduced to analytically integrate the heat diffusion equation impairs its ability to predict solidus and liquidus line positions whenever the magnitude of latent heat of fusion exceeds a certain value.
Źródło:
Chemical and Process Engineering; 2018, 39, 1; 85-102
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic analysis of cast irons solidification with various types of graphite
Autorzy:
Elbel, T.
Hampl, J.
Powiązania:
https://bibliotekanauki.pl/articles/380412.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pomiar aktywności tlenu
energia swobodna Gibbsa
krzepnięcie żeliwa
continuous oxygen activity measurement
calculation of Gibbs free energy
cast iron solidification
Opis:
The contribution summarises the results of oxygen activity determinations, which were measured and registered continuously in castings from cast irons with various types of graphite. The results were used to find the relationship between two variables: natural logarithm of oxygen activities and reverse value of thermodynamic temperature 1 /T. Obtained regression lines were used to calculate oxygen activity at different temperatures, to calculate Gibbs free energy \deltaG at the different temperatures and to calculate the single \deltaG value for significant temperature of the graphite solidification. The results were processed by a statistical analysis of data files for the different types of graphite with flake, vermicular and spheroidal graphite. Each material has its proper typical oxygen activities range and individual temperature function of Gibbs free energy for analysing and governing casting quality.
Źródło:
Archives of Foundry Engineering; 2012, 12, 4; 157-165
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Projekt stanowiska eksperymentalnego do badania krzepnięcia w przestrzeni walcowej
The test stand project to analysis solidification in cylinder space
Autorzy:
Gortych, M.
Gortych, A.
Powiązania:
https://bibliotekanauki.pl/articles/372677.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
proces krzepnięcia
konwekcja swobodna
powierzchnia walcowa
solidification process
free convection
cylindrical space
Opis:
W pracy przedstawiono projekt stanowiska eksperymentalnego do badania procesu krzepnięcia wokół powierzchni cylindrycznej. Scharakteryzowano proces konwekcji swobodnej i proces krzepnięcia wokół walca poziomego i pochylonego. Przedstawiono rozkład lokalnych wartości współczynnika przejmowania ciepła przy opływie poprzecznym walca poziomego. Przedstawiono połączenie zjawiska krzepnięcia i konwekcji swobodnej cieczy wokół przestrzeni walcowej.
The paper presents an experimental design to test the position of the solidification process around the cylindrical surface. Characterized the convection and solidification process around the horizontal cylinder and inclined. The distribution of the local heat transfer coefficient of the flow around a transverse horizontal cylinder. A combination solidification phenomena and convection of the liquid around the cylindrical surface.
Źródło:
Zeszyty Naukowe. Inżynieria Środowiska / Uniwersytet Zielonogórski; 2014, 154 (34); 22-29
1895-7323
Pojawia się w:
Zeszyty Naukowe. Inżynieria Środowiska / Uniwersytet Zielonogórski
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Simulation of Solidification Microstructure based on Adaptive Octree Grids
Autorzy:
Yin, Y.
Li, Y.
Wu, K.
Zhou, J.
Powiązania:
https://bibliotekanauki.pl/articles/947350.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
isothermal solidification
binary alloy
numerical simulation
phase field model
microsegregation
microstructure
krzepnięcie izotermiczne
stop dwuskładnikowy
symulacja numeryczna
Opis:
The main work of this paper focuses on the simulation of binary alloy solidification using the phase field model and adaptive octree grids. Ni-Cu binary alloy is used as an example in this paper to do research on the numerical simulation of isothermal solidification of binary alloy. Firstly, the WBM model, numerical issues and adaptive octree grids have been explained. Secondary, the numerical simulation results of three dimensional morphology of the equiaxed grain and concentration variations are given, taking the efficiency advantage of the adaptive octree grids. The microsegregation of binary alloy has been analysed emphatically. Then, numerical simulation results of the influence of thermo-physical parameters on the growth of the equiaxed grain are also given. At last, a simulation experiment of large scale and long-time has been carried out. It is found that increases of initial temperature and initial concentration will make grain grow along certain directions and adaptive octree grids can effectively be used in simulations of microstructure.
Źródło:
Archives of Foundry Engineering; 2016, 16, 2; 33-40
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies on solidification of wastes from metal coating
Autorzy:
Banaszkiewicz, K.P.
Marcinkowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/777946.pdf
Data publikacji:
2007
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
stabilizacja/solidyfikacja
cement portlandzki
piasek
odpady poflotacyjne
osady galwaniczne
metale ciężkie
stabilization/solidification
Portland cement
sand
flotation tailings
galvanic sludges
heavy metals
Opis:
There are over 1000 electroplating workshops functioning in Poland; they are agglomerated in automotive industry, agricultural and construction machines industry, precision instruments industry, electronics, electrotechnics, etc.. . The chemical composition of wastes from galvanizing plants strictly depends on the technological processes as well as the methods of neutralization of industrial wastewaters. The wastes mentioned can be neutralized, among other possibilities, using cement, fly ashes or lime. The material that gains the widest applicability for treating a wide spectrum of hazardous wastes is Portland cement. Using cement enables an improvement of the physical (solidifying) and chemical characteristics of various kinds of wastes, that ensures a decrease in the mobility of contaminants (stabilization). The process using Portland cement (CEM I 32,5 R) was used towards galvanic sludges. The results presented in this article allow for the assesment of the applicability of mixture of cement with mortar sand, as well as the mixture of cement and flotation tailings for the stabilizing and solidifying galvanic sludge, containing mainly Cr, Cu, Zn and Ni. The presented study was also concentrated on the limitation in the transport of leached contaminants to the environment, the reduction of the solubility of hazardous contaminants, as well as a change in the physical structure of the waste - in other words, derivation of the product that could be mechanically durable during transport and storage.
Źródło:
Polish Journal of Chemical Technology; 2007, 9, 3; 51-55
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical model of solidification of cast composite with particles
Model numeryczny krzepnięcia kompozytu z cząstkami
Autorzy:
Ciesielski, M.
Domański, Z.
Mochnacki, B.
Powiązania:
https://bibliotekanauki.pl/articles/395939.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
kompozyt
krzepnięcie
model matematyczny krzepnięcia
cast composite
solidification
numerical modelling
control volume method
Opis:
In the paper the numerical model of heat transfer in non-homogeneous domain (cast composite) is considered. The composite is formed by the spherical particles (Pb) and the metal matrix (Al). Initial temperatures of components correspond to solid state (particle) and liquid one (matrix). The heat is transferred from the aluminum matrix and absorbed by the lead particle. The 3D problem, i.e. the cubic control volume with single spherical particle located at the center part of the cube, is considered. A numerical algorithm corresponding to the discussed mathematical model of the boundary-initial problem is constructed on the basis of control volume method and some examples of numerical results are shown.
Praca dotyczy wymiany ciepła pomiędzy osnową i cząstkami tworzącymi materiał kompozytowy. W szczególności rozpatrywana jest objętość kontrolna (Al) w kształcie sześcianu, w którego środku umieszczona zostaje cząstka (Pb). Wymiary rozpatrywanej objętości kontrolnej zależą od gęstości cząstek wprowadzonych do osnowy. Założono, że objętość kontrolna umieszczona jest w centralnej części odlewanego kompozytu oraz, że warunki brzegowe zadane na powierzchni odlewu i formy nie wpływają na procesy cieplne w tej objętości. Oznacza to, że warunki przyjęte na powierzchniach granicznych sześcianu to warunki adiabatyczne. Równania różniczkowe i warunki brzegowe zapisano w konwencji entalpowej zakładając, że krzepnięcie osnowy i topnienie cząstek zachodzą w stałej temperaturze. Rozpatrywaną objętość kontrolną dzielono na 503 sześcianów. Do obliczeń numerycznych wykorzystano metodę bilansów elementarnych, przyjmując że pola temperatur w ciekłej osnowie i cząstce ołowianej są znane w chwili początkowej oraz, że kontakt między podobszarami układu jest idealny. W trakcie procesu obserwowano topnienie cząstki ołowianej i stygnięcie osnowy. W pracy przedstawiono wyniki symulacji numerycznych w postaci krzywych nagrzewania i stygnięcia w wybranych punktach obszarów, jak również przebieg izoterm w przekroju kompozytu dla kilku wybranych czasów. Ponadto zbadano wpływ zmian udziału objętościowego cząstki w osnowie na przebieg procesu wymiany ciepła.
Źródło:
Civil and Environmental Engineering Reports; 2010, 5; 123-132
2080-5187
2450-8594
Pojawia się w:
Civil and Environmental Engineering Reports
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic Assessment of Mushy Zone in Directional Solidification
Autorzy:
Mikołajczak, P.
Ratke, L.
Powiązania:
https://bibliotekanauki.pl/articles/380005.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aluminum alloy
directional solidification
mushy zone
CALPHAD technique
Fe intermetallics
β-Al5FeSi
stop aluminium
krzepnięcie kierunkowe
strefa półciekła
technika CALPHAD
Opis:
Solidification of AlSiFe alloys was studied using a directional solidification facility and the CALPHAD technique was applied to calculate phase diagrams and to predict occurring phases. The specimens solidified by electromagnetic stirring showed segregation across, and the measured chemical compositions were transferred into phase diagrams. The ternary phase diagrams presented different solidification paths caused by segregation in each selected specimen. The property diagrams showed modification in the sequence and precipitation temperature of the phases. It is proposed in the study to use thermodynamic calculations with Thermo-Calc which enables us to visualize the mushy zone in directional solidification. 2D maps based on property diagrams show a mushy zone with a liquid channel in the AlSi7Fe1.0 specimen center, where significant mass fraction (33%) of β-Al5FeSi phases may precipitate before α-Al dendrites form. Otherwise liquid channel occurred almost empty of β in AlSi7Fe0.5 specimen and completely without β in AlSi9Fe0.2. The property diagrams revealed also possible formation of α–Al8Fe2Si phases.
Źródło:
Archives of Foundry Engineering; 2015, 15, 4; 101-109
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of solidification parameters and macrostructure of IN-713C castings after complex modification
Autorzy:
Binczyk, F.
Gradoń, P.
Powiązania:
https://bibliotekanauki.pl/articles/379884.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nickel alloy
superalloy
modification
inoculation
solidification
thermal analysis
macrostructure
stop niklu
nadstop
modyfikacja
inokulacja
krzepnięcie
analiza termiczna
makrostruktura
Opis:
The paper presents a research results concerning impact of volume modification (ceramic filter containning cobalt aluminate and hafnium powder) and simultaneous surface and volume modification on solidification and stereological parameters of macrostructure of castings made from post-production scrap of nickel superalloy IN-713C. Research included investigation of the influence of chemical composition on the temperature Tliq i Tsol and evaluation of following macrostructure parameters: the number of grains per mm2, average grain area and shape coefficient. Results indicate high influence of carbon content on Tliq. Macrostructure of sample castings indicate positive effect of surface and volume modification, however impact of surface modification is more pronounced.
Źródło:
Archives of Foundry Engineering; 2013, 13, 3; 5-8
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stress-rupture Tests of MAR-M-509 Cobalt Alloy Improved by Rapid Solidification
Autorzy:
Mróz, M.
Orłowicz, W.
Tupaj, M.
Powiązania:
https://bibliotekanauki.pl/articles/380367.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
MAR-M509 cobalt alloy
rapid solidification
stress rupture test
stop kobaltu MAR-M509
krystalizacja szybka
Opis:
In the paper, results of stress-rupture test applied to MAR-M-509 cobalt alloy specimens, in as-cast condition and with microstructure shaped under rapid solidification conditions are presented. The material for the study were castings of MAR-M509 alloy obtained by means of the investment casting method. The rapid solidification conditions were obtained by means of remelting process carried out with the use of GTAW method. The effect of rapid solidification following the remelting process is a refinement of microstructure in castings of MAR-M509 alloy and significant extension of the time to rupture in stress-rupture test.
Źródło:
Archives of Foundry Engineering; 2013, 13, 1 spec.; 117-120
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of Side Feeders Systems by Means of Simulation of Solidification
Autorzy:
Perzyk, M.
Kozlowski, J.
Mazur, M.
Szymczewski, K.
Powiązania:
https://bibliotekanauki.pl/articles/382649.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
solidification process
castings defect
side feeders
simulation
design rules
proces krzepnięcia
wada odlewu
podajnik
zasady projektowania
Opis:
Simulation software can be used not only for checking the correctness of a particular design but also for finding rules which could be used in majority of future designs. In the present work the recommendations for optimal distance between a side feeder and a casting wall were formulated. The shrinkage problems with application of side feeders may arise from overheating of the moulding sand layer between casting wall and the feeder in case the neck is too short as well as formation of a hot spot at the junction of the neck and the casting. A large number of simulations using commercial software were carried out, in which the main independent variables were: the feeder’s neck length, type and geometry of the feeder, as well as geometry and material of the casting. It was found that the shrinkage defects do not appear for tubular castings, whereas for flat walled castings the neck length and the feeders’ geometry are important parameters to be set properly in order to avoid the shrinkage defects. The rules for optimal lengths were found using the Rough Sets Theory approach, separately for traditional and exothermic feeders.
Źródło:
Archives of Foundry Engineering; 2015, 15, 1; 69-74
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
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