Atomistic simulations for the effects of stacking fault energy on defect formations by displacement cascades in FCC metals under Poisson’s deformation
Atomistic simulations for the effects of stacking fault energy on defect formations by displacement cascades in FCC metals under Poisson’s deformation
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DOI：
10.1007/s10853-019-03688-1
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发表时间：
2019-05
影响因子：
4.5
通讯作者：
Sho Hayakawa;T. Okita;M. Itakura;T. Kawabata;Katsuyuki Suzuki
中科院分区：
文献类型：
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作者：
Sho Hayakawa;T. Okita;M. Itakura;T. Kawabata;Katsuyuki Suzuki
我们进行了分子动力学模拟的位移级联FCC金属泊松变形下使用不同的层错能（SFE）的原子间势，为了研究拉伸应变对SFE依赖的缺陷形成过程的影响。在无应变和施加应变的条件下，残余缺陷的数量和缺陷团的尺寸分布均不依赖于SFE，而应变在一定程度上促进了缺陷的形成。我们还观察到，应变影响的自间隙原子（SIA）团簇的形成取决于它们的大小和伯格斯矢量。这些结果与基于缺陷形成能的分析一致。同时，在较低的SFE下，无应变和施加应变下，SIA完美环的数量较高，导致随着SFE的降低，滑动SIA团簇的比例增加。此外，SIA完美环的绝对数量增加所施加的应变，而SFE的SIA完美环的数量的依赖性不受影响。这些发现与SIA完美环和SIA弗兰克环之间的形成能量差异有关。从这项研究中提取的见解显着有助于在辐照下的核材料，特别是低SFE金属，如奥氏体不锈钢的微观结构演变的建模。
We performed molecular dynamics simulations of displacement cascades in FCC metals under Poisson’s deformation using interatomic potentials differing in stacking fault energy (SFE), in order to investigate the effect of tensile strain on the SFE dependence of defect formation processes. There was no clear SFE dependence of the number of residual defects and the size distribution of defect clusters under both no strain and the applied strain, while the strain enhanced the defect formation to a certain extent. We also observed that the strain affected the formations of self-interstitial atom (SIA) clusters depending on their size and the Burgers vector. These results were consistent with the analysis based on the defect formation energies. Meanwhile, the number of SIA perfect loops was higher at lower SFE under both no strain and the applied strain, leading to an increase in the ratio of glissile SIA clusters with a decrease in SFE. Further, the absolute number of SIA perfect loops was increased by the applied strain, while the SFE dependence of the number of SIA perfect loops was not affected. These findings were associated with the difference in formation energy between an SIA perfect loop and an SIA Frank loop. The insights extracted from this study significantly contribute to the modeling of microstructural evolution in nuclear materials under irradiation, especially for low SFE metals such as austenitic stainless steels.