Unstable stacking fault energy and Peierls stress for evaluating slip system competition in body-centered cubic metals
Unstable stacking fault energy and Peierls stress for evaluating slip system competition in body-centered cubic metals
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DOI：
10.1016/j.jmrt.2022.12.162
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发表时间：
2022-12
期刊：
影响因子：
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通讯作者：
Xuechen Zhang;Shuo Cao;Lian-Ji Zhang;R. Yang;Q. Hu
中科院分区：
文献类型：
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作者：
Xuechen Zhang;Shuo Cao;Lian-Ji Zhang;R. Yang;Q. Hu
确定体心立方 (BCC) 金属中 {110}⟨ 111⟩、{112}⟨ 111⟩ 和 {123}⟨ 111⟩ 滑移系统之间的竞争对于了解其机械性能非常重要。本文计算了一系列BCC金属的三个滑移系的不稳定堆垛层错能(γ u s)和Peierls应力(σ p)，以评估它们之间的竞争。我们发现 BCC 金属的 γ u s 与 (B+ G)/a 2/3 成正比，其中 B、G 和 a 分别是体积模量、剪切模量和晶格常数。 γ u s s 的计算预测{110}⟨ 111⟩位错滑移优先于{112}⟨ 111⟩和{123}⟨ 111⟩滑移，然而，γ u s 不能用于识别后两个滑移的优先级，因为这两个滑移系统的 γ u s 彼此太接近。根据 σ p s，对于除 K 之外的所有金属，位错的迁移率按 {110}⟨ 111⟩、{112}⟨ 111⟩、{123}⟨ 111⟩ 的顺序递减。值得注意的是，γ u s 和 σ p 彼此之间不是单调相关的。
Determining the competition between the {110}⟨ 111⟩,{112}⟨ 111⟩ and {123}⟨ 111⟩ slip systems in body-centered cubic (BCC) metals is important to understand their mechanical properties. In this paper, the unstable stacking fault energy (γ u s) and Peierls stress (σ p) of the three slip systems of a series of BCC metals are calculated in order to evaluate the competition among them. We find that γ u s of BCC metals is proportional to (B+ G)/a 2/3, where B, G and a are the bulk modulus, shear modulus and lattice constant, respectively. The calculations of γ u s s predict that the {110}⟨ 111⟩ dislocation slip is prior to the {112}⟨ 111⟩ and {123}⟨ 111⟩ slips, however, γ u s may not be used to identify the priorities of the latter two slips because γ u s s of these two slip systems are too close to each other. According to σ p s, the mobility of dislocations decreases in the sequence of {110}⟨ 111⟩,{112}⟨ 111⟩,{123}⟨ 111⟩ for all the metals considered except for K. Noticeably, it is shown that γ u s and σ p are not monotonically related to each other.