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Tytuł:
Deformation Microstructure And Texture Transformations In FCC Metals Of Medium-To-High Stacking Fault Energy: Critical Role Of Micro- And Macro-Scale Shear Bands
Zmiany mikrostrukturalne i teksturowe w odkształconych metalach o sieci RSC o średniej i wysokiej energii błędu ułożenia: krytyczna rola mikro- i makro-pasm ścinania
Autorzy:
Paul, H.
Miszczyk, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/353921.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
shear bands
texture
SEM/EBSD
copper
AA1050 alloy
plane strain compression
pasma ścinania
tekstura
miedź
stop AA1050
Opis:
Microstructure and texture development in medium-to-high stacking fault energy face centred cubic metals were investigated in order to examine the role of lattice re-orientation on slip propagation across grain boundaries and to characterize the influence of micro- and macro-scale copper-type shear bands on textural changes at large deformations. Polycrystalline pure copper (fine - and coarse - grained) and fine-grained AA1050 alloy were deformed in plane strain compression at room temperature to form two sets of well-defined macroscopic shear bands. The deformation-induced sub-structures and local changes in crystallographic orientations were investigated mostly by scanning electron microscopy equipped with high resolution electron backscattered facility. In all the deformed grains within macro- shear bands a strong tendency to strain-induced re-orientation was observed. The flat, strongly deformed grains exhibited a deflection within narrow areas. The latter increased the layers’ inclination with respect to ED and led to kink-type bands, which are the precursors of MSBs. The mechanism of macro- / micro-shear bands formation is strictly crystallographic since in all the areas of the sheared zone, the crystal lattice rotated such that one of the {111} slip planes became nearly parallel to the shear plane and the <011> direction became parallel to the direction of maximum shear. This strain-induced crystal lattice rotation led to the formation of specific macro- / micro-shear bands components that facilitated slip propagation across the grain boundaries without any visible variation in the slip direction.
W pracy badano zmiany strukturalne i teksturowe w metalach o sieci regularnej ściennie centrowanej związane z lokalną re-orientacją sieci krystalicznej wynikającą z formowania się mikro- i makro- pasm ścinania. Analizowano polikrystaliczne próbki miedzi oraz aluminium o czystości technicznej (stop AA1050) odkształcane w temperaturze otoczenia w próbie nieswobodnego ściskania do zakresu odkształceń, w których następuje wyraźne uformowanie się dwóch rodzin makroskopowych pasm ścinania. W badaniach wykorzystano skaningowy mikroskop elektronowy wyposażony w system automatycznego pomiaru orientacji lokalnych. Zaobserwowano, że w ziarnach umiejscowionych w obszarze makroskopowych pasm ścinania występuje ściśle zdefiniowana tendencja rotacji sieci krystalicznej, w wyniku której jedna z płaszczyzn typu {111} przyjmuje położenie zbliżone do położenia płaszczyzny ścinania, a jeden z kierunków typu <110> (lub <112>) wykazuje tendencję do sytuowania się równolegle do kierunku ścinania. Obserwowana w obszarze wnętrza pasm ścinania rotacja prowadzi do uformowania się specyficznej (mikro)tekstury, która umożliwia propagację poślizgów poprzez granice ziaren bez ‘istotnej’ zmiany kierunku ścinania.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 3; 2235-2246
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Mechanism of Corrosion of Steel 304L in the Presence of Copper in Industrial Installations
Mechanizm korozji stali austenitycznej 304L w obecności miedzi w instalacjach przemysłowych
Autorzy:
Lachowicz, M. M.
Lachowicz, M. B.
Powiązania:
https://bibliotekanauki.pl/articles/354474.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
austenitic steel
copper
pitting corrosion
mechanism of corrosion
stal austenityczna
miedź
korozja wżerowa
mechanizm korozji
Opis:
This paper presents the mechanism of corrosion of austenitic steel in the presence of copper. It has been found that when corrosion occurs, the presence of copper in the corrosive solution in the neighbourhood of austenitic steel results in the intensification of the corrosion processes. In the macroscopic scale, austenitic steel constitutes a cathode, but since copper precipitates can deposit on it, the steel can locally pass to the active state and become an anode in the places where copper deposited, which leads to its local corrosion due to galvanic corrosion.
W pracy przedstawiono mechanizm korozji stali austenitycznej w obecności miedzi. Stwierdzono, że w przypadku wystąpienia korozji stali austenitycznej w obecności miedzi, prowadzi to do intensyfikacji zachodzących procesów korozyjnych. W skali makroskopowej stal austenityczna stanowi katodę, jednak możliwość osadzania się na niej wydzieleń miedzi powoduje, że lokalnie może ona przejść w stan aktywny i w tych miejscach stać się anodą, co prowadz do jej lokalnej korozji wskutek wystąpienia korozji galwanicznej.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 4; 2657-2662
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microalloying of Continuous Cast Aluminum Strip and Structural Modification Using Plastic Treatment to a 9 μm Foil (Patent no. 39762, P-377/76)
Autorzy:
Purenović, M. M.
Purenović, Jelena M.
Baralić, J. Č.
Powiązania:
https://bibliotekanauki.pl/articles/2203751.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
microalloying
modified continuous cast aluminum strip
nano oxide film
corrosion stability
plasticity
superplasticity
equiaxed structure
strain hardening
surface tension
crystallization zone
dendrites
crystal twinning
Opis:
Innovative procedure of microalloying continuous cast aluminum strip, thickness 10 mm, by Be, Zr and Mn using 3C Pechiney technology (no. 39762, P-377/76), and modifying the existing parameters for strip casting and crystallization was implemented under industrial conditions with two randomly selected batches 2×8 tones, without previous selection of standardized quality of aluminum, purity Al 99.5%, obtained by electrolysis. The application of microalloying and overall structural modification of the technology resulted in obtaining nanoscale, ultra-thin, compact oxide high-gloss film with uniform surface of continuous cast strip, instead of the usual thick and porous oxide film. The outcome of microalloying the obtained equiaxed fine-grained nano/micro structure was avoiding anisotropic and dendritic microstructure of the strip, and improving deformation and plastic properties of modified continuous cast strip subjected to the technology of plastic treatment by rolling until the desired foil thickness of 9 μm was obtained. The invention of microalloying and structural modification, including multiplying effect of several components, directly or indirectly, changed numerous structurally-sensitive properties. The obtained nano/micro structure of crystal grains with equiaxed structure resulted in the synergy of undesirable <111> and inevitable <100> and <110> textures. Numerous properties were significantly enhanced: elastic modulus was improved, and intensive presence of cracks in warm forming condition was prevented due to rapid increase of the number of grains to 10000 grains/cm2 in as-cast state.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 1; 345--357
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hot deformation behavior of Mg-Zn-Al alloy tube processed by severe plastic deformation
Autorzy:
Fata, A.
Faraji, G.
Mashhadi, M. M.
Tavakkoli, V.
Powiązania:
https://bibliotekanauki.pl/articles/352771.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PTCAP
AZ31 tube
grain refinement
hot deformation
High ductility
Opis:
In the current study, severe plastic deformation (SPD) was applied on a commercial Mg-3Al-1Zn alloy tubes via parallel tubular channel angular pressing (PTCAP) route. Different passes of PTCAP process were applied, and microstructure, hardness and tensile properties at the room, and elevated temperatures were evaluated. The results showed that bimodal microstructure appeared and led to AZ31 alloy represented higher hardness, higher strength with a reasonable elongation at room temperature. Similarly, very high elongation to failure was achieved at a higher temperature. The increase in the number of SPD passes up to two, leads to increasing the ductility up to 263% at 400°C. Then, an increase in the number of PTCAP passes to three, leads to decrease in the ductility as the results of formation of microvoids when SPD processing at higher equivalent strains without a sufficient hydrostatic compressive stress. Relatively ductile fracture mode was also occurred in all samples.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 1; 159-166
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructural and Chemical Composition Changes in the Bonding Zone of Explosively Welded Sheets
Autorzy:
Paul, H.
Miszczyk, M. M.
Gałka, A.
Chulist, R.
Szulc, Z.
Powiązania:
https://bibliotekanauki.pl/articles/352017.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
explosive welding
SEM
TEM
multilayered clads
reactive metals
amorphous phase
nano-grained phases
Opis:
In this work, the effect of heat transfer during explosive welding (EXW) and post-processing annealing on the microstructural and chemical composition changes have been thoroughly analysed using scanning and transmission electron microscopies and X-ray synchrotron radiation. Several combination of explosively welded metal compositions were studied: Ti with Al, Cu with Al, Ta or stainless steel, stainless steel with Zr or Ta and Ti with carbon steel. It was found that the melted metals exhibit a strong tendency to form brittle crystalline, nano-grained or even amorphous phases during the solidification. For all analysed metal combinations most of the phases formed in the zones of solidified melt do not appear in the equilibrium phase diagrams. Concurrently, the interfacial layers undergo severe plastic deformation forming nano-grained structures. It has been established that these heavily deformed areas can undergo dynamic recovery and recrystallization already during clad processing. This leads to the formation of new stress-free grains near the interface. In the case of low temperature and short time post processing annealing only the melted zones and severely deformed layers undergo recovery and recrystallization. However, drastic changes in the microstructure occurs at higher temperature and for longer annealing times. Applying such conditions leads to diffusion dominant processes across the interface. As a consequence continuous layers of intermetallic phases of equilibrium composition are obtained.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 2; 683-694
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of weld fusion zone for TIG welded P91and P92 steels
Autorzy:
Pandey, C.
Mahapatra, M. M.
Kumar, P.
Thakare, J. G.
Powiązania:
https://bibliotekanauki.pl/articles/353653.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
P91
P92
fusion zone
microstructure
TIG
Opis:
The welding of nuclear grade P91 and P92 steel plate of thickness 5.2 mm were performed using the autogenous tungsten inert gas (TIG) welding process. The welded joint of P91 and P92 steel plate were subjected to the varying post weld heat-treatment (PWHT) including the post weld heat treatment (PWHT) and re-austenitizing based tempering (PWNT). A comparative study was performed related to the microstructure evolution in fusion zone (FZ) of both the welded joint using the scanning electron microscope and optical microscope in a different condition of heat treatment. The hardness test of the FZ for both joints was also conducted in a different condition of heat treatment. P92 steel welded joint have observed the higher tendency of the δ ferrite formation that led to the great variation in hardness of the P92 FZ. The homogeneous microstructure (absence of δ ferrite) and acceptable hardness was observed after the PWNT treatment for both the welded joint.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 4; 1755-1761
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Comparative Study of Residual Stress and Mechanical Properties for FSW and TIG Weld on Structural Steel
Autorzy:
Chaurasia, P. K.
Pandey, C.
Giri, A.
Saini, N.
Mahapatra, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/354742.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
FSW
TIG
residual stress
microstructure
hardness
Opis:
Mechanical properties and residual stresses of friction stir welded and autogenous tungsten inert gas welded structural steel butt welds have been studied. Friction stir welding (FSW) of structural steel butt joints has been carried out by in-house prepared tungsten carbide tool with 20 mm/min welding speed and 931 rpm tool rotation. Tungsten inert gas (TIG) welding of the butt joints was carried out with welding current, arc voltage and the welding speed of 140 amp, 12 V and 90 mm/min respectively. Residual stress measurement in the butt welds has been carried out in weld fusion zone and heat affected zone (HAZ) by using blind hole drilling method. The magnitude of longitudinal residual stress along the weld line of TIG welded joints were observed to be higher than friction stir welded joint. In both TIG and FSW joints, the nature of longitudinal stress in the base metal was observed to be compressive whereas in HAZ was observed to be tensile. It can be stated that butt welds produced with FSW process had residual stress much lower than the autogenous TIG welds.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 1019-1029
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication and Characterization of Al6061-Nano Al2O3 Composites by Ultrasonic Assisted Stir Casting followed by Heat Treatment and Hot Forging
Autorzy:
Purohit, Rajesh
Qureshi, M.M.U.
Kumar, Ashish
Mishra, Abhishek
Rana, R.S.
Powiązania:
https://bibliotekanauki.pl/articles/28099519.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Al6061 alloy
Al6061-Al2O3 nanocomposites
XRD analysis
FESEM
mechanical properties
automotive gears
Opis:
The present work comprises the development of Al6061/nano Al2O3 composites with 0 to 4 weight percent in steps of 0.5 wt. % of nano alumina particles by using ultrasonic assisted stir casting. Casted samples were subjected to heat treatment and hot forging. Further forged and heat-treated gear blanks of nano Al2O3 (0 to 3.0 weight %) reinforced nanocomposites were machined to make spur gears for the wear test. The results have shown that nano Al2O3 reinforcement in the Al6061 matrix with heat treatment and forging improves the hardness and compressive strength up to 3.5 wt. %, after that, it starts decreasing because of the agglomeration of nano alumina particles. SEM results reveal grain refinement of the pure alloy after reinforcement. Removal of porosity and voids observed after forging operation. Wear resistance increasing with incorporation of Al2O3 nanoparticles in base alloy, reinforcement wt. %, precipitation hardening and hot forging also improves wear resistance and mechanical properties. These composites have widespread applications in gear, brake discs, crankshaft, clutch plates, pistons, and other components of automobiles and aircraft structures.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 2; 791--798
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microhardness Evolution in Relation to the Crystalline Microstructure of Aluminum Alloy AA3004
Autorzy:
Izairi, N.
Ajredini, F.
Vevecka-Pfiftaj, A.
Makreski, P.
Ristova, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/353733.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al alloy
AA3004
equal-channel angular pressing
ECAP
microhardness
SEM
grain size
XRD
Opis:
Equal-channel angular pressing (ECAP) was used as a technique for severe plastic deformation (SPD) on Al alloy AA3004. This technique produced fully dense materials of refined grain structure to sub-micrometer dimensions and advanced mechanical properties. The ECAP processing of samples was conducted as 1 to 4 passes through the die at room temperature. We present the results of the studied homogeneity evolution with the ECAP treatment. Furthermore, a Scanning Electron Microscope (SEM) was used for examination of the microstructure changes in samples undergone from 1 to 4 passes. The microhardness-HV increased upon each ECAP pass. The resulting micro-hardness evolution was attributed to crystalline microstructure modifications, such as the d-spacing (studied by X-ray Diffraction-XRD) depending on the number of ECAP pressings. The microcrystalline changes (grain refining evaluated from the Scanning Electron Microscopy - SEM images) were found to be related to the HV, following the Hall-Petch equation.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1101-1108
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Grit Blasting and Thermal Spraying on Microstructure Evolution of P91 Weldment
Autorzy:
Thakare, J. G.
Pandey, C.
Mulik, R. S.
Mahapatra, M. M.
Narang, H. K.
Powiązania:
https://bibliotekanauki.pl/articles/947576.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
P91
HAZ
IC-HAZ
deformation zone
Opis:
In the present work, studies have been carried out on the variations in the microstructure and hardness of P91 base-metal and welded joint. This variations result from the grit blasting and thermal cycle experienced during the thermal spraying process. The microstructural effects have been analyzed in terms of the depth of the deformation zone. Scanning Electron Microscopy and Xray diffraction were used as characterization techniques. The grit blasting carried out prior to thermal spraying has resulted in the highest change in sub-surface hardness of the heat affected zone (HAZ). However, flame treatment further reduced the subsurface hardness of the heat affected zone. The depth of deformation zone was highest for inter-critical heat affected zone (IC-HAZ). The overall coating process resulted in an increase in subsurface hardness of various regions of HAZ and fusion zone (FZ). The base metal showed a 7% increase in subsurface hardness due to the overall coating process. The IC-HAZ showed maximum variation with 36% increase in subsurface hardness. The coarse grained heat affected zone (CG-HAZ) and FZ did not show any change in subsurface hardness. As a whole, the hardness and microstructure of the welded joint was observed to be more sensitive to the thermal spray coating process as compared to the base metal.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 4; 1725-1734
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nanocrystalline TiO2 Powder Prepared by Sol-Gel Method for Dye-Sensitized Solar Cells
Autorzy:
Dobrzański, L. A.
Szindler, M. M.
Szindler, M.
Lukaszkowicz, K.
Drygała, A.
Prokopiuk vel Prokopowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/353118.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sol-gel
nanopowder
titanium dioxide
dye-sensitized solar cell
Opis:
In this study titanium dioxide nanopowder has been manufactured and examined. Nanocrystalline TiO2 powder has been obtained by hydrolysis and peptization of a solution of titanium isopropoxide and isopropanol. Subsequently, produced powder has been subjected to structural analysis by using a transmission electron microscope, X-ray diffractometer, and Raman spectrometer. For comparison purposes, a commercially available titanium dioxide powder (i.e. titanium white) was also used. Thin layers have been made from this powder and further have been examined by using a UV/VIS spectrometer. Completed research shows the nanocrystalline structure of obtained layers and their good properties such as absorbance at the range of wavelength equal 200 - 1000 nm.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2A; 833-836
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extraction of Tannic Acid from Kenaf Bast Fibre using Ultrasonic Assisted Extraction
Autorzy:
Mohamad, Mardawani
Ibrahim, H. A.
Nasir, M. F. M.
Mohidem, Nur Atikah
Shoparwe, N. F.
Teo, Pao Ter
Masri, Mohamad Najmi
Irfan, Abd Rahim
Powiązania:
https://bibliotekanauki.pl/articles/2134102.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasonic assisted extraction
UAE
sonication time
duty cycle
extraction process
kenaf bast fibre
Opis:
Tannic acid or tannin, type of phenolic compound contains in kenaf bast fibre. Conventional extraction has certain limitations in terms of time, energy, and solvent consumption. Ultrasound assisted extraction (UAE) can extract bioactive components in shorter time, low temperature, with lesser energy and solvent requirement. UAE as alternative extraction technique is better equipped to retain the functionality of the bioactive compounds. In this study, the conditions for ultrasound assisted extraction (UAE) of tannic acid from kenaf bast fibre by assessing the effect of sonication time and different duty cycles were optimized. The use of ultrasound to extract tannic acid from kenaf bast fiber was evaluated. Ultrasound-assisted extraction (UAE) was carried out using ethanol as solvent to intensify the extraction efficacy. Phytochemical screening was conducted to identify the presence of tannic acid in extracts. The extracts then were analyzed using High-Performance Liquid Chromatography (HPLC) and Scanning Electron Microscopy (SEM). It was found that 0.2429 mg/mL of tannic acid was obtained under the extraction conditions of extraction temperature of 40℃, sonication time of 20 minutes and duty cycle of 50%. From SEM analysis, it was found that the raw sample demonstrated rough surface and no porous but kenaf bast fibre display smoother surface with less impurities and few pores appeared after the extraction process using UAE. These results indicate that ultrasound-assisted extraction is an efficient method for extracting tannic acid from kenaf bast fibre with the advantages of lower extraction time and higher extraction yield.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 3; 1061--1066
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Calcination Temperature on Structural and Optical properties of ZnO-SiO2 Nanocomposite by Simple Thermal Treatment Route
Autorzy:
Alibe, I. M.
Matori, K. A.
Aziz, S. H. A.
Yazid, Y.
Saion, E.
Alibe, A. M.
Zaid, M. H. M.
Ghapur Engku, E. A. A.
Zangina, T.
Powiązania:
https://bibliotekanauki.pl/articles/351868.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
optical properties
calcination
phosphor
nanocomposite
Opis:
This study offers a new method to synthesize facilely willemite (Zn2 SiO4 ) based phosphor at the temperature of 800°C. The ZnO-SiO2 nanocomposite was calcined at different temperatures between 500 and 1000°C. The structural, morphological and optical properties of the nanocomposite obtained at various calcination temperatures were studied using different techniques. The FT-IR, XRD and the UV-vis result confirmed the formation of willemite phase. The precursor was confirmed to be amorphous by XRD at room temperature, but upon calcination temperature at 500°C, it was transformed into a crystalline structure. The crystallinity and the particle size of the nanocomposite increase as the calcination temperature were increased as revealed by XRD and TEM measurement. The sample exhibits a spherical morphology from 500 to 800°C and dumbbell-like morphology above 800°C as shown by the FESEM images. The absorption spectrum suffers intense in lower temperature and tends to shift to lower wavelength in the UV region as the calcination temperature increases. The band gap values were found to be increasing from 3.228-5.550 eV obtained between 500 to 1000°C, and all the results confirm the formation of willemite phase at 800°C.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 539-545
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Destructive Mechanisms Occurring in the Surface Layer of Forging Tools Used in Hot Forging Processes
Autorzy:
Hawryluk, M.
Zwierzchowski, M.
Marciniak, M.
Powiązania:
https://bibliotekanauki.pl/articles/354152.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
destruction mechanisms
non-lubricated forging tools
uncooled forging tools
laboratory abrasive wear
thermal fatigue test stands
Opis:
In the work was presented the results of studies concerns on the destructive mechanisms for forging tools used in the wheel forging process as well the laboratory results obtained on a specially constructed test items for testing abrasive wear and thermal fatigue. The research results of the forging tools shown that the dominant destructive mechanisms are thermal fatigue occurring in the initial the exploitation stage and abrasive wear, which occurs later, and is intensified effects of thermo-mechanical fatigue and oxidation process. In order to better analysis of phenomena associated with destructive mechanisms, the authors built a special test stands allow for a more complete analysis of each of the mechanisms separately under laboratory conditions, which correspond to the industrial forging processes. A comprehensive analysis of the forging tools confirmed by laboratory tests, showed the interaction between the thermal fatigue and abrasive wear, combined with the oxidation process. The obtained results showed that the process of oxidation and thermal fatigue, very often occur together with the mechanism of abrasive wear, creating a synergy effect. This causing the acceleration, the most visible and easily measurable process of abrasive wear.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 941-952
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Composite Ag-La0.8Sr0.2 MnO3-σ cathode for solid oxide fuel cells
Kompozytowa katoda Ag-La0.8Sr0.2 MnO3-σ dla stałotlenkowych ogniw paliwowych
Autorzy:
Mosiałek, M.
Przybyła, M.
Tatko, M.
Nowak, P.
Dudek, M.
Zimowska, M.
Powiązania:
https://bibliotekanauki.pl/articles/355057.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
intermediate-temperature solid oxide fuel cells
silver-LSM composite cathode
oxygen reduction reaction
stałotlenkowe ogniwa paliwowe
katody kompozytowe z metalicznego srebra
reakcja redukcji tlenu
Opis:
Composite cathodes for solid oxide fuel cells composed of metallic silver dispersed in ceramic (Ag-La0.8 Sr0.2 MnO3-σ ) matrix were prepared on the surface of solid electrolyte by two-step procedure. First the matrix of controlled porosity was created by sintering mixture of Ag-La0.8 Sr0.2 MnO3-σ powder with the organic polymer beads then the matrix was saturated with AgNO3 solution and sintered again. Such obtained cathodes showed higher electrical conductivity and lower charge transfer resistance in oxygen reduction reaction in comparison to pure ceramic cathodes.
Na powierzchni elektrolitu stałego wytwarzano kompozytowe katody dla stałotlenkowych ogniw paliwowych zbudowane z metalicznego srebra rozproszonego w osnowie z Ag-La0.8 Sr0.2 MnO3-σ .Osnowę o kontrolowanej porowatości otrzymywano przez prażenie mieszaniny proszku Ag-La0.8 Sr0.2 MnO3-σ z kulkami z tworzywa organicznego. Porowatą osnowę nasycano roztworem AgNO3 i ponownie wyprażano. Tak otrzymane katody wykazywały wyższą przewodność elektryczną i niższą oporność aktywacyjną w reakcji redukcji tlenu w porównaniu z katodami z czystej ceramiki.
Źródło:
Archives of Metallurgy and Materials; 2013, 58, 4; 1337-1340
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł

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