Movement of Kirkendall markers, second phase particles and the Type 0 boundary in two-phase diffusion couple simulations

2004 ◽  
Vol 52 (7) ◽  
pp. 1917-1925 ◽  
Author(s):  
K. Wu ◽  
J.E. Morral ◽  
Y. Wang
Keyword(s):  
Diffusion Couple ◽  
Second Phase ◽  
Two Phase ◽  
Phase Diffusion ◽  
Second Phase Particles

3D MС Simulation of Grain Growth Kinetics and the Zener Limit in Polycrystals

2014 ◽  
Vol 598 ◽  
pp. 8-12
Author(s):  
K.R. Phaneesh ◽  
Anirudh Bhat ◽  
Gautam Mukherjee ◽  
Kishore T. Kashyap
Keyword(s):  
Monte Carlo ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Large Scale ◽  
Volume Fraction ◽  
Growth Exponent ◽  
Cube Root ◽  
Second Phase ◽  
Two Phase ◽  
Second Phase Particles

Large scale Potts model Monte Carlo simulation was carried on 3-dimensional square lattices of 1003 and 2003 sizes using the Metropolis algorithm to study grain growth behavior. Simulations were carried out to investigate both growth kinetics as well as the Zener limit in two-phase polycrystals inhibited in growth by second phase particles of single-voxel size. Initially the matrices were run to 10,000 Monte Carlo steps (MCS) to check the growth kinetics in both single phase and two-phase poly-crystals. Grain growth exponent values obtained as a result have shown to be highest (~ 0.4) for mono-phase materials while the value decreases with addition of second phase particles. Subsequently the matrices were run to stagnation in the presence of second phase particles of volume fractions ranging from 0.001to 0.1. Results obtained have shown a cube root dependence of the limiting grain size over the particle volume fraction thus reinforcing earlier 3D simulation efforts. It was observed that there was not much difference in the values of either growth kinetics or the Zener limit between 1003 and 2003 sized matrices, although the results improved mildly with size.

scholarly journals Influence of Grain Refinement on Oxidation Behavior of Two-Phase Cu–Cr Alloys at 973–1,073 K in Air

2016 ◽  
Vol 35 (10) ◽  
pp. 1005-1011
Author(s):  
T. J. Pan ◽  
J. Chen ◽  
Y. X. He ◽  
W. Wei ◽  
J. Hu
Keyword(s):  
Grain Size ◽  
Spatial Distribution ◽  
Oxidation Behavior ◽  
Second Phase ◽  
Two Phase ◽  
Reactive Component ◽  
Parabolic Law ◽  
Second Phase Particles ◽  
Kinetics Of ◽  
Lower Oxidation

AbstractThe oxidation behavior of grain-refined Cu–7.0 Cr alloy (GR Cu–7.0 Cr) in air at 973–1,073 K was investigated in comparison with normal casting Cu–7.0 Cr alloy (CA Cu–7.0 Cr). The oxidation of CA Cu–7.0 Cr alloy nearly followed parabolic law, while the oxidation kinetics of GR Cu–7.0 Cr slightly deviated from parabolic law. Both alloys almost produced multi-layered scales consisting of the outer layer of CuO and the inner layer of mixed Cr2O3 and Cu2O oxides plus internal oxidation zones of chromium. The grain-refined Cu–7.0 Cr alloy produced a more amount of Cr2O3 in the inner layer of the scale, and thus was oxidized at much lower oxidation rate than that of CA Cu–7.0 Cr with normal grain size. The experimental results indicated that the differences in oxidation behavior between two alloys may be ascribed to the different size and spatial distribution of the second-phase particles and the reactive component contents in localized zone.

Investigation of a New Type of Al3Ti-Based Ll2 Alloy With Second Phase Precipitation

1994 ◽  
Vol 364 ◽  
Author(s):  
Gengxiang Hu ◽  
Jian Sun ◽  
Xiaojun Weng ◽  
Tong Li ◽  
Shipu Chen
Keyword(s):  
Single Phase ◽  
Solution Treatment ◽  
Second Phase ◽  
Quaternary Alloys ◽  
Two Phase ◽  
Ti Alloys ◽  
Second Phase Particles ◽  
New Type ◽  
Temperature Aging ◽  
Nb Additions

AbstractSince the L12 structured Al3Ti alloy exists only in a narrow compositional range, further alloying of the single phase Ll2 alloy to improve its property seems hardly successful. Developing two-phase or multiphase Al3Ti alloys may be an effective approach for strengthening and toughening. In this article, a new type of Al3Ti-based alloy which has a Ll2 matrix with precipitates of a second phase is reported. The quaternary alloys based on Al67Mn8Ti25, and modified with Nb additions, consist of an Ll2 matrix and DO22 second phase particles in the annealed state, but the second phase can be dissolved by solution treatment and precipitated during high temperature aging. Remarkable strenghtening and promising compressive ductility were exhibited by the experimental alloy. The influence of composition on the microstructure and properties of the alloys are reported also.

Measuring and Modelling the Microstructures of Two-Phase Aluminium Alloys after Deformation

2012 ◽  
Vol 715-716 ◽  
pp. 23-32 ◽  
Author(s):  
John F. Humphreys ◽  
Pete S. Bate ◽  
Ali Gholinia ◽  
Ian Brough
Keyword(s):  
Aluminium Alloys ◽  
Second Phase ◽  
Two Phase ◽  
New Techniques ◽  
Deformation Microstructure ◽  
Deformation Structures ◽  
Deformable Particles ◽  
Second Phase Particles ◽  
Cold Rolled ◽  
Ebsd Method

The effect of second-phase particles on the deformation and annealing behaviour of metals is re-assessed in the light of some new techniques. Using an EBSD method which provides much improved angular resolution, the effect of small non-deformable particles on the homogeneity of the deformation microstructure has been quantified. The presence of micron sized second-phase particles alters the deformation microstructure adjacent to particles, and a 3-d investigation of the deformation structures associated with large (>1μm) second-phase particles in cold rolled aluminium alloys has been carried out using 3-d FIB sectioning combined with EBSD, and the microstructures compared with the predictions of 3-d CPFEM modelling. The effects of grain orientation, strain and particle size have been investigated, and the results compared with earlier TEM investigations of such microstructures.

Thoughts on Superplasticity in General and on its Role in Earth Deformation

2012 ◽  
Vol 735 ◽  
pp. 3-8
Author(s):  
John Wheeler
Keyword(s):  
Grain Boundary Sliding ◽  
Diffusion Creep ◽  
Large Strains ◽  
Second Phase ◽  
Two Phase ◽  
Phase Diffusion ◽  
Shape Alignment ◽  
The Earth ◽  
Materials Modelling ◽  
Boundary Sliding

The Earth deforms dominantly by solid-state creep. Diffusion creep is known to be important. It is less clear whether mechanisms in which grain boundary sliding is accompanied by other processes (dislocation activity), and/or are associated with stress exponents closer to 2 than to 1 are important. Since the mechanisms of superplasticity are themselves not fully resolved, we cannot say for sure whether the Earth deforms superplastically. Models for diffusion creep are relevant for the Earth and possibly for superplastic materials. Modelling shows that large strains may not necessarily obliterate initial textures because grain rotations, although they occur, slow down as microstructures evolve. Modelling also predicts major strength anisotropy induced by grain shape alignment. Models for two-phase diffusion creep can be constructed for when the second phase is inert (insoluble). If both phases are soluble and can participate in diffusion, the basic theory for single phase diffusion creep cannot be applied and new insight is required.

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