Microstructure & Phase Transformation in Rapidly Solidified V-Ga Alloys

1986 ◽  
Vol 80 ◽  
Author(s):  
M. W. Park ◽  
S. H. Whang ◽  
S. Karmarkar ◽  
D. Divecha
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Grain Refinement ◽  
Rapid Solidification ◽  
Rapid Quenching ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rapidly Solidified ◽  
A15 Phase

AbstractThe A15 Phase forming V-Ga alloys were processed into ribbons and foils by rapid solidification techniques. Microstructures and phase transformation in these alloys by rapid solidification and succeeding heat treatment were investigated by x-ray diffraction and TEM. It is shown that equilibrium A15 phases can readily be suppressed by rapid quenching in these alloys. A significant grain refinement resulting from the rapid solidification also was observed. Microhardnesses of these alloys as a function of Ga concentration were determined.

Rapidly Solidified Al-6Si-3Cu Alloy

2008 ◽  
Vol 570 ◽  
pp. 103-108 ◽  
Author(s):  
C. Triveño Rios ◽  
Claudemiro Bolfarini ◽  
Walter José Botta Filho ◽  
Claudio Shyinti Kiminami
Keyword(s):  
Rapid Solidification ◽  
X Ray Diffraction ◽  
Type Alloy ◽  
X Ray ◽  
Optical Scanning ◽  
Transmission Electron ◽  
Al2cu Phase ◽  
Solidification Processes ◽  
Dendritic Arm Spacing ◽  
Rapidly Solidified

Rapid solidification processes, RSP, are powerful tools to induce microstructural modifications, which may improve mechanical properties of alloys. In this paper the influence of rapid solidification on the formation of the undesirable brittle intermetallic compounds promoted by Si and Fe in Al-6Si-3Cu (A319-type) alloy have been investigated. The alloy have been casted using both conventional method and water-cooled wedge-copper mould. The microstructures have been evaluated by using a combination of X-ray diffraction, optical, scanning and transmission electron microscopy, and by Vickers microhardness. By increasing the cooling rate the length of the intermetallic β-Al5FeSi phase decreased, accompanying the same tendency of the secondary dendritic arm spacing. These results are accompanied by an increasing in hardness. Moreover, the formation and growth of the Al2Cu phase have been suppressed. These microstructural and hardness changes with the rapid solidification might be attributed to the increased solid solution content of the elements in the Al matrix.

Study on the Law of Phrase Transformation of High-Carbon Matrix Steel 4Cr-3Mo-3V-2W

2011 ◽  
Vol 284-286 ◽  
pp. 1610-1614
Author(s):  
Shun Sang Na ◽  
Jian Sha Chen ◽  
Chao Fu ◽  
Guo Tao Zhang ◽  
Qian Xu
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Phase Analysis ◽  
Carbon Matrix ◽  
Residual Austenite ◽  
X Ray Diffraction ◽  
High Carbon ◽  
X Ray ◽  
Metallographic Observation ◽  
Alloy Carbide

The study on the phase transformation law of High-Carbon Matrix steel 4Cr-3Mo-3V-2W-Ni-Nb, which is processed in different heat treatment, is conducted by means of metallographic observation, hardness determination and phase analysis conducted with the help of X-ray diffraction. The results indicate what is as follow: through quenching at 970°C, the main precipitations of alloy carbide are V4WC5, Cr7C3 and Fe3W3C at 200~300°C, V4WC5 and Cr7C3 at 400°C, V4WC5 and Cr7C3 at 500°C, V4WC5, Cr7C3 and Mn23C6 at 600°C. The transformation of residual austenite is thorough completed above 400 °C and the cause of secondary hardening is the precipitation of V4WC5 and V4C2.67.

Rapid Solidification Microstructures and Precipitation in AL-Mn Alloys

1983 ◽  
Vol 28 ◽  
Author(s):  
R. J. Schaefer ◽  
D. Shechtman ◽  
F. S. Biancaniello
Keyword(s):  
Rapid Solidification ◽  
Growth Kinetics ◽  
Melt Spinning ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rapidly Solidified ◽  
Solidification Microstructures ◽  
Al Matrix

ABSTRACTRapidly solidified Al containing up to to 15 wt.% Mn was prepared by melt spinning. The alloys were examined by TEM and X-ray diffraction in the as-spun condition and after annealing at 450°C. Four precipitate phases were detected, and their growth kinetics were correlated to subgrain structures in the Al matrix.

Effect of Fe on Phase Transformation of Low Temperature Cu-Al-Mn Memory Alloy

2011 ◽  
Vol 687 ◽  
pp. 474-479
Author(s):  
Kun Peng Zhu ◽  
Ning Hu ◽  
Fu Shun Liu
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Sharp Increase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fe Content ◽  
Heat Treated ◽  
Scanning Electron ◽  
Al Matrix ◽  
Fe Addition

The influence of Fe addition on the phase transformation and the microstructure of Cu67Al27-XMn6FeXshape memory alloys are investigated by means of electrical resistivity, X-ray diffraction, scanning electron microscopy and microhardness test. It was shown that the Ms (Martensitic start transformation) temperature of the 850°C heat-treated alloy exhibit a sharp increase as Fe content increases, by comparison with the alloy without heat-treatment. For example, after 850°C heat-treatment, the Ms temperature of the alloy increases from 52K to 135K when Fe is added from 0 at.% to 1.5 at.%. The microstructure of as-homogenized Cu67Al27-XMn6FeXalloys consists of Cu3Al matrix, γ2(Cu9Al4) and α (Cu) phases. Fe element was distributed in precipitates and matrix.

Temperature Effect on Chicken Egg Shell Investigated by XRD, TGA and FTIR

2008 ◽  
Vol 55-57 ◽  
pp. 333-336 ◽  
Author(s):  
Kittisakchai Naemchanthara ◽  
S. Meejoo ◽  
Wandee Onreabroy ◽  
Pichet Limsuwan
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Ir Spectroscopy ◽  
Water Absorption ◽  
Calcium Oxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Temperatures ◽  
Egg Shell ◽  
Anadara Granosa

The main purpose of this work is to study the structure of Anadara granosa shell sample and its structural transformation upon heat treatments. The sample was ground and characterized as powder throughout this work. Structural identifications of all samples were characterized, and determined qualitatively by using X-ray diffraction, IR spectroscopy and thermogravimetry measurement (TGA). It was found that the specimen is made of aragonite, a common phase of CaCO3 mineral. The powder sample was annealed at specific temperatures over the range of 200°C - 900°C and the effects of heat treatment on the structure of Anadara granosa shell samples were studied. The results show that aragonite transforms to calcite at the temperatures between 200°C and 400°C and completely becomes calcite between 400-500°C. Then, the calcite transforms to calcium oxide at the temperatures between 500°C - 900°C. The exact structures and quantities of phase at different annealing temperatures were studied by Rietveld refinement. In our study, we also used IR spectroscopy and TGA to study the effect of water absorption of the samples on the phase transformation.

Icosahedral phase formation in rapidly quenched aluminum-ruthenium alloys

1988 ◽  
Vol 3 (3) ◽  
pp. 421-425 ◽  
Author(s):  
Steven M. Anlage ◽  
Brent Fultz ◽  
Kannan M. Krishnan
Keyword(s):  
Electron Microscopy ◽  
Phase Diagram ◽  
Rapid Solidification ◽  
Phase Formation ◽  
Metastable Phase ◽  
Icosahedral Phase ◽  
Rapid Quenching ◽  
Metastable Phase Diagram ◽  
X Ray Diffraction ◽  
X Ray

Systematic rapid quenching experiments on the icosahedral phase-forming system Al1 − xRux were performed for × < 20 at. %. The solidified alloys have been studied by electron microscopy and x-ray diffraction to determine their composition, constituent phases, and phase morphology. It has been determined that the icosahedral phase must form directly from the liquid and, at these quench rates, is always found in the presence of second or third phases. The results have been summarized in a metastable phase diagram appropriate for rapid solidification of Al1 − xRux at piston and anvil quench rates. This metastable phase diagram describes the results for Ru concentrations less than 14 at. %.

Water Absorption and Phase Transition of Calcium Carbonate in the Sea Water Mussel (Anadara Granosa)

2008 ◽  
Vol 55-57 ◽  
pp. 329-332
Author(s):  
W. Siriprom ◽  
Wandee Onreabroy ◽  
Pichet Limsuwan
Keyword(s):  
Phase Transition ◽  
Heat Treatment ◽  
Phase Transformation ◽  
Ir Spectroscopy ◽  
Water Absorption ◽  
Sea Water ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Temperatures ◽  
Anadara Granosa

The main purpose of this work is to study the structure of Anadara granosa shell sample and its structural transformation upon heat treatments. The sample was ground and characterized as powder throughout this work. Structural identifications of all samples were characterized, and determined qualitatively by using X-ray diffraction, IR spectroscopy and thermogravimetry measurement (TGA). It was found that the specimen is made of aragonite, a common phase of CaCO3 mineral. The powder sample was annealed at specific temperatures over the range of 200°C - 900°C and the effects of heat treatment on the structure of Anadara granosa shell samples were studied. The results show that aragonite transforms to calcite at the temperatures between 200°C and 400°C and completely becomes calcite between 400-500°C. Then, the calcite transforms to calcium oxide at the temperatures between 500°C - 900°C. The exact structures and quantities of phase at different annealing temperatures were studied by Rietveld refinement. In our study, we also used IR spectroscopy and TGA to study the effect of water absorption of the samples on the phase transformation.

Metastable ordered austenite in rapidly solidified Fe-Al-C alloys

1989 ◽  
Vol 47 ◽  
pp. 516-517
Author(s):  
J. A. Sarreal
Keyword(s):  
Rapid Solidification ◽  
Melt Spinning ◽  
X Ray Diffraction ◽  
Austenitic Phase ◽  
X Ray ◽  
Transmission Electron ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Equilibrium Phases ◽  
Rapidly Solidified

Conventionally cast Fe-Al-C alloys are extremely brittle containing combinations of ferrite, carbide and other phases. Rapid solidification has the potential of altering the microstructure to subsequently change the resulting mechanical properties. An apparent conflict exist concerning the effect of rapid solidification on the resulting microstructure of these alloys. Inoue and co-workers, using transmission electron microscopy (TEM) and electron diffraction analyses, reported the presence of several non-equilibrium phases including austenite (fcc - γ) and ordered austenite (Ll2-γ') structures on alloys containing 1.7 to 2.1 C and 6 to 12 Al in weight % (w/o) on melt spun ribbons 30 μm in thickness. Han and Choo, using x-ray diffraction analysis on 30-48 μm thick melt spun ribbons concluded that this ordered fee phase is rather an austenitic phase in which phase decomposition accompanied by sideband phenomenon had occured.Single roller melt spinning technique was used to make ribbons 35-70 μm thick and 0.5-5 mm wide. X-ray diffration analysis showed single phase austenite for samples 2-6 w/o AI and 2 w/o C. Samples with 8-10 w/o AI and 2 w/o C also showed several superlattice lines in addition to the fundamental fcc peaks.

A Study of Rhombohedral Phase in Y2 O3 -Partially Stabilized Zirconia

1986 ◽  
Vol 78 ◽  
Author(s):  
Jukishige Kitano ◽  
Y. Mori ◽  
A. Ishitani ◽  
T. Masaki
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Hot Isostatic Pressing ◽  
Tetragonal Zirconia ◽  
Rhombohedral Phase ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
X Ray ◽  
The Stability

ABSTRACTTetragonal to rhombohedral phase transformation was studied by X-ray diffraction technique on the ground surfaces of tetragonal zirconia polycrystals (Y-TZP) and partially stabilized zirconia (Y-PSZ) with 2.0 to 5.0 mol% Y2 O3 contents prepared by hot isostatic pressing. The rhombohedral phase increased with increase of Y2 O3 content from 2.0 to 5.0 mol%, and also with the increase of HIPing temperature from 1400 to 1600°C. The stability of the phase was also studied with regard to the surface finish and annealing. The subsequent heat treatment of the samples was found to promote the reverse rhombohedral to tetragonal transformation.

Effect of Heat Treatment on the Microstructure and Magnetic Properties of As-Cast SmCo5-Based Alloys

2012 ◽  
Vol 190 ◽  
pp. 204-207
Author(s):  
Vladimir P. Menushenkov ◽  
T.A. Sviridova ◽  
E.V. Shelekhov ◽  
L.M. Belova ◽  
Alexey P. Menushenkov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Phase Transformation ◽  
Heat Treatments ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystalline Structures ◽  
Microstructure And Magnetic Properties

Local and crystalline structures of as-cast SmCo5±xalloys subjected to various heat treatments were studied using EXAFS, X-ray diffraction, and metallographic analyses. XRD and EXAFS analyses of SmCo5-xalloys show the evidence of the Sm-enrichment of the SmCo5phase. The behavior of the lattice parameters of SmCo5phase in Sm-rich alloys during aging between 1120°C and 700°C can be related to the phase transformation of SmCo5into SmCo5-xphases.

Sign in / Sign up

Export Citation Format

Share Document