Effect of heating temperature and cooling rate on the phase composition of VT23 alloy

1987 ◽  
Vol 29 (3) ◽  
pp. 236-239
Author(s):  
A. A. Il'in ◽  
M. Yu. Kollerov ◽  
M. G. �kimyan ◽  
V. V. Alekseev
Keyword(s):  
Phase Composition ◽  
Cooling Rate ◽  
Heating Temperature ◽  
Vt23 Alloy

The Effect of Heating on Phase Composition of the Cr3C2- Ti System Hard Alloys Fabricated by the Explosive Compaction of Powder Mixtures

2019 ◽  
Vol 945 ◽  
pp. 617-622 ◽  
Author(s):  
V.O. Kharlamov ◽  
Aleksandr Vasilevich Krokhalev ◽  
S.V. Kuz’min ◽  
V.I. Lysak
Keyword(s):  
Phase Composition ◽  
Chromium Carbide ◽  
Heating Temperature ◽  
Calculated Data ◽  
Fine Powder ◽  
Hard Alloys ◽  
Explosive Compaction ◽  
X Ray ◽  
Diffusion Layers ◽  
Equilibrium Phases

The article reports findings on theoretically-calculated data and experimental results obtained with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy methods of the analysis of hard alloys produced by the explosive compaction of the Cr3C2 chromium carbide powders with titanium, first in the original condition and then after heating to 1200 °C. It was established that when heated to 600 °С the phase composition of hard alloys does not change and corresponds to the composition of the original components of the powder mixture. When the heating temperature was increased to 650 °С, new fine powder fractions emerged at the “chromium carbide – titanium” interface. At the temperature of 700 °С two separate diffusion layers emerged and grew in the opposite directions. Due to this growth the source phases in the alloy fully disappeared at 1200 °С and two equilibrium phases were formed.

The Effect of Microwave Irradiation on Structural and Mechanical Properties of Nano-Structured Bone-Like Carbonated Hydroxyapatite

2011 ◽  
Vol 493-494 ◽  
pp. 231-235 ◽  
Author(s):  
Mina Khorami ◽  
Saeed Hesaraki ◽  
Touradj Ebadzadeh ◽  
Sajad Farhangdoust ◽  
Ali Zamanian
Keyword(s):  
Phase Composition ◽  
Microwave Irradiation ◽  
Bending Strength ◽  
Heating Temperature ◽  
Total Porosity ◽  
Carbonated Hydroxyapatite ◽  
Carbonated Apatite ◽  
Mtt Method ◽  
Before And After

Nanocrystalline carbonated hydroxyapatite was produced through hydraulic conversion of calcium phosphate cement in simulated body fluid (SBF) and then heated in a microwave oven at 1000-1250 °C. The phase composition and microstructures were evaluated, before and after the thermal processing, using XRD and SEM, respectively. Total porosity and bending strength of the samples were also tested. Proliferation and morphology of osteoblastic cells on samples were evaluated using MTT method. Limited growth of apatite crystals was observed by the thermal treatment in which the samples exhibited a crystal size of ~ 150 nm at heating temperature of 1250 º. Based on the results, the microwave irradiation led to a little change in phase composition of carbonated apatite and slight amount of β-TCP phase was found together with large amount of apatite. The sample irradiated at 1250 °C formed more dense material having bending strength value up to 130 % that of unheated sample. The in vitro cell studies showed that the microwave irradiated samples could provide adequate cell proliferation and attachment.

Investigation of the High Strength Steel Al-Si Coating during Hot Stamping Operations

2009 ◽  
Vol 410-411 ◽  
pp. 289-296 ◽  
Author(s):  
Francesca Borsetto ◽  
Andrea Ghiotti ◽  
Stefania Bruschi
Keyword(s):  
Surface Roughness ◽  
Cooling Rate ◽  
High Strength Steel ◽  
Room Temperature ◽  
Heating Temperature ◽  
Hot Stamping ◽  
High Strength ◽  
Tribological Behaviour ◽  
Metal Sheets ◽  
Coating Characteristics

To improve the low formability that HSS sheets exhibit at room temperature, innovative forming technologies like the hot stamping process are currently applied. In order to avoid scaling and decarburization during the heating step, metal sheets coated with a specially developed Al-Si coating are utilized. In the present work the coating characteristics in terms of morphology, surface roughness and tribological behaviour are investigated as function of heating temperature, holding time and cooling rate that are typical of hot stamping processes.

Effect of the cooling rate on the phase composition of crystallized CdGeAs2 melts

2017 ◽  
Vol 62 (12) ◽  
pp. 1645-1651 ◽  
Author(s):  
A. N. Aronov ◽  
S. F. Marenkin ◽  
I. V. Fedorchenko
Keyword(s):  
Phase Composition ◽  
Cooling Rate

Microstructure Characterization of Ni-75 at.% Al Raney Type Alloy as a Result of Cooling Rate and Chromium Doping

MRS Advances ◽  
2019 ◽  
Vol 4 (25-26) ◽  
pp. 1441-1447
Author(s):  
Naveed Hussain ◽  
Andrew M Mullis ◽  
Jennifer S Forrester
Keyword(s):  
Catalytic Activity ◽  
Phase Composition ◽  
Cooling Rate ◽  
Rietveld Refinement ◽  
Volume Fraction ◽  
Size Fraction ◽  
Standard Size ◽  
Globular Structure ◽  
Cooling Rates ◽  
Size Fractions

ABSTRACTThe effect of cooling rate on the phase composition of gas atomized Raney type catalysts was studied using the Ni-75 at.% Al composition. The resulting particles were sieved into 3 standard size fractions and analysed using XRD with Rietveld refinement: as expected the three phases, Al₃Ni₂, Al₃Ni, and Al-Al₃Ni eutectic were identified. Differing phase compositions in the 3 size ranges were identified offering a possible explanation for varying catalytic activity with cooling rate, the higher cooling rates experienced by the smaller droplets allow less time for the peritectic conversion of Al₃Ni₂ to Al₃Ni to proceed. This in turn results in a more Al-rich residual liquid, increasing the volume fraction of eutectic. This was further confirmed when analysing the microstructure using SEM backscatter imaging. Al₃Ni₂ was found to be encased in a shell of Al₃Ni characteristic of peritectic reactions. The remainder of the alloy was found to consist of Al-Al₃Ni eutectic. The SEM backscatter imaging also indicated that the larger particles displayed and a more globular structure than smaller particles. Similar Raney type Ni-75 at.% Al doped with 1.5 at.% Cr were synthesised using the same method and sieved into the same 3 standard size fractions. It was found that the Cr doped alloys exhibited a more dendritic character than the undoped samples in the corresponding size fraction, although the material still displayed an increasingly dendritic character with increasing cooling rate. The phase composition found by Rietveld refinement also followed a similar trend to the undoped samples with decreasing amounts of Al₃Ni formed at the higher cooling rates. However, significant amounts of an additional phase, Al₁₃Cr₂, were also observed. Rietveld refinement found that a larger amount of Al₁₃Cr₂ was present than could be accounted for by the addition of 1.5 at.% Cr . This can be explained by the substitution of Ni onto the Cr lattice, as confirmed by Rietveld refinement. Al₁₃Cr₂ was found to be located mostly at the boundary of the Al₃Ni and Al-Al₃Ni eutectic phases during elemental mapping and quantitative image analysis of backscattered electron micrographs. This indicates that precipitation of Al₁₃Cr₂ is towards the end of the solidification process. The relatively large amounts of the Al-rich Al₁₃Cr₂ may explain the enhanced catalytic activity observed following leaching of Cr-doped Raney catalysts.

scholarly journals STUDY OF THE STRUCTURE AND PHASE COMPOSITION OF THE OXIDE FILM ON THE SURFACE OF A LAYERED COATING OF THE Al-Ni SYSTEM

2020 ◽  
pp. 14-18
Author(s):  
V. G. Shmorgun ◽  
A. I. Bogdanov ◽  
V. P. Kulevich ◽  
R. D. Evchits
Keyword(s):  
Phase Composition ◽  
Oxide Film ◽  
Heating Temperature ◽  
Atmospheric Oxygen ◽  
Complex Oxide ◽  
Protective Oxide ◽  
Layered Coating ◽  
Protective Oxide Film ◽  
Temperature Heating ◽  
High Temperature Heating

This work is aimed to the study of the structure and phase composition of the oxide film formed on the surface of the layered coating of the Al-Ni system during high-temperature heating. It was experimentally established that at the initial stages of heat treatment, as a result of the interaction of the Al-Ni system layered coating with atmospheric oxygen, separate sections of Al2O3 oxide are formed on its surface, which are agglomerates of plate crystals of α-modification of nanometer thickness, which increase and grow together with increasing exposure time continuous protective oxide film. An increase in the heating temperature leads to an intensification of oxidation processes and the formation of a complex oxide film of AlO and spinel NiAlO.

Thermal-Mechanical Simulation of the Controlled Rolling and Cooling Process by Orthogonal Design for Pipeline Steel

2012 ◽  
Vol 557-559 ◽  
pp. 2355-2360 ◽  
Author(s):  
Min Jiang ◽  
Li Na Chen ◽  
Wei Pang ◽  
Chong He Li ◽  
Xiong Gang Lu
Keyword(s):  
Cooling Rate ◽  
Heating Temperature ◽  
Pipeline Steel ◽  
Great Influence ◽  
Control Process ◽  
Controlled Rolling ◽  
Rolling Temperature ◽  
Cooling Temperature ◽  
Finish Rolling Temperature ◽  
Finish Rolling

A novel pipeline steel was prepared by the vacuum inducting technology, using Gleeble-3500 hot simulator, its parameters of thermo-mechanical control process (TMCP), such as heating temperature, finish rolling temperature, finish cooling temperature and cooling rate, have been studied by the orthogonal experiment with four factors and three levels. Through the orthogonal theoretical analysis, it is found that the sequence of the effect of parameters on the mechanical property is: Cooling rate > Heating temperature > Finish cooling temperature > Finish rolling temperature, the cooling rate is the most important factor affecting the inspection target and possesses a great influence on the hardness of the pipeline steel.

Microstructures Development in Al-5Fe and Al-5Fe-3Y Alloys Solidified at Different Cooling Rate

2011 ◽  
Vol 189-193 ◽  
pp. 2462-2466
Author(s):  
Guo Fa Mi ◽  
Cui Fen Dong ◽  
Chang Yun Li ◽  
Hai Yan Wang
Keyword(s):  
Rare Earth ◽  
Phase Composition ◽  
Intermetallic Compound ◽  
Cooling Rate ◽  
Melt Spinning ◽  
Metastable Phase ◽  
Vacuum Melting ◽  
Suction Casting ◽  
Rapidly Solidified

Cast, sub-rapidly solidified and rapidly solidified Al-5Fe alloy and Al-5Fe-3Y alloy were respectively prepared by vacuum melting, suction casting and melt spinning. The effect of increasing cooling rate and adding rare earth Y alloy on microstructures and phase composition were investigated. The results showed that the acicular Al3Fe phase transferred to spherical phase and dispersed secondary precipitations were also found when 3.0 wt% Y was added in the Al-5Fe alloy. Meanwhile, the microstructures were apparently refined by the increasing of cooling rate. The metastable phase A16Fe and intermetallic compound A110Fe2Y phase have been observed in Al-5Fe alloy and Al-5Fe-3Y alloy, respectively.

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