Yi Wang, Huai Yu Hou, Xiang Bing Liu, Rong Shan Wang, Jing Tao Wang
The kinetics of coherent Cu rich precipitation in Fe-Cu and Fe-Cu-Ni alloys during thermal ageing have been modeled by Atomic Kinetic Monte Carlo method (AKMC). The AKMC is parameterized by existing ab-inito data to treat vacancy mediated diffusion which is depend on local atomic environment. A nonlinear semi-empirical time adjusting method is proposed to rescaled the MC time. The combined AKMC and time adjusting method give good agreement with experiments and other simulations, including advancement factor and the Cu cluster mobility. Simulations of ternary alloys reveal Ni has a temporal delay effect on Cu precipitation. This effect is caused by the decreasing diffusion coefficient of Cu clusters. And the reduction effect of diffusion coefficient weakens with cluster size. The simulations can be used to explain the experimental phenomenon that higher cluster number density formed during coasening stage in Fe-Cu-Ni alloys than corresponding binary alloy, which is related to cluster mobility.
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http://arxiv.org/abs/1212.6900
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