Relation between grain growth and grain-boundary diffusion in a pure material by molecular dynamics simulations

2006 ◽  
Vol 54 (15) ◽  
pp. 4053-4061 ◽  
Author(s):  
V YAMAKOV ◽  
D MOLDOVAN ◽  
K RASTOGI ◽  
D WOLF
2016 ◽  
Vol 83 (10) ◽  
Author(s):  
J. B. Allen

The present work serves to document the development and findings associated with a wavelet-based multiscale simulation analysis for anisotropic grain growth of a two-dimensional polycrystalline material. In particular, lattice-based Monte Carlo and atomically-based Molecular Dynamics simulations are used to compute the grain boundary energies over their respective spatial domains. Serial coupling is performed utilizing an orthonormal set of Haar wavelet transforms embedded within a corresponding multiresolution analysis. For the Monte Carlo approach, anisotropies in grain boundary energies, caused by differences in grain orientation (texturing), are examined using two distinct methods, while the molecular dynamics simulations, offering inherent anisotropy, are conducted assuming the interatomic Lennard Jones potential. Among other findings, under the present context, the results confirm the viability of the wavelet-based multiresolution analysis (MRA) method for use as a potential coupling agent, and provide substantiation for its use with other applications. The results further offer quantitative comparisons between isotropic and anisotropic modeling results, and demonstrate their range of applicability.


2004 ◽  
Vol 52 (7) ◽  
pp. 1971-1987 ◽  
Author(s):  
A.J. Haslam ◽  
V. Yamakov ◽  
D. Moldovan ◽  
D. Wolf ◽  
S.R. Phillpot ◽  
...  

2012 ◽  
Vol 715-716 ◽  
pp. 415-415
Author(s):  
Elizabeth A. Holm ◽  
Stephen M. Foiles

Molecular dynamics simulations of bicrystals show that grain boundaries undergo a thermal roughening transition, and the grain boundary mobility increases abruptly when the boundary roughens. The roughening transition temperature varies widely from boundary to boundary, ranging from less than 0.4 to more than 0.9 of the melting temperature. Thus, at typical annealing temperatures we expect polycrystals to contain both smooth (slow) and rough (fast) boundaries, with the fraction of each type varying with temperature.


1999 ◽  
Vol 601 ◽  
Author(s):  
B.-N. Kim ◽  
K. Hiraga

AbstractSuperplastic tensile deformation is simulated in 2 dimensions by incorporating grain boundary diffusion and concurrent grain growth derived from static and dynamic growth mechanisms. The following relationship is found between microstructural changes and deformation behavior for constant stress conditions. Grain boundary diffusion produces an increase in the aspect ratio of the matrix grains during deformation and the increased aspect ratio causes a change in creep rate parameters: the stress exponent is decreased from the initial value of 1.0 for equiaxed grains and the grain size exponent is increased from the initial value of 3.0. Accelerated grain growth is also found by the present simulation.


2013 ◽  
Vol 1 (4) ◽  
pp. 220-227 ◽  
Author(s):  
Christian Brandl ◽  
Timothy C. Germann ◽  
Alejandro G. Perez-Bergquist ◽  
Ellen K. Cerreta

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