Effect of damage rate on the kinetics of void nucleation and growth by phase field modeling for materials under irradiations

JOURNAL OF NUCLEAR MATERIALS

卷:480

Article

Ding, Xuejian¹  Zhao, Jiejiang¹  Huang, Hao¹  Ding, Shurong¹  Huo, Yongzhong¹ 

[1] Fudan Univ, Dept Mech & Engn Sci, Shanghai 200433, Peoples R China

关键词: Modified Cahn-Hilliard equation;    Explicit nucleation algorithm;    Vacancy generation and accumulation;    Void formation and growth kinetics;    Irradiation effects;   

DOI  :  10.1016/j.jnucmat.2016.08.008

来源: Elsevier

【 摘 要 】

The void formation and growth in materials under irradiations is studied by a modified Cahn-Hilliard equation coupled with the explicit nucleation algorithm. Through the numerical simulations, the stages of incubation, nucleation, growth and coalescence of the irradiation induced voids are clearly observed with a faster kinetics for stronger damage rate. There seems to exist a critical damage rate g(v)(c) at which the kinetics speeds up significantly. For smaller damage rates, very few voids can be nucleated. But the nucleated voids can grow rather large with its average radius growing as R(v)(alpha)t(1/d). For stronger irradiations, much more voids could be nucleated, but they cannot grow very large before coarsening. The growth follows a much faster kinetics asR(v)(alpha)t(2/d), The critical damage rate gt should be determined by the competition of the rate of diffusion and the rate of vacancy production due to irradiations. (c) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

Free