变形结合在bcc和中的变形结合的起源
Jianwei Xiao1, Songwei Li1, Xiaoxiao Ma1
1Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, China.
Physical review letters
|October 13, 2023
概括
变形生发生在压缩下的和纳米晶体中,由于稳定双胞胎胚胎. 这项研究揭示了这些过渡金属中这种意想不到的双胞胎机制的物理起源.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 计算材料科学科学 计算材料科学
背景情况:
- 在体中心立方 (bcc) 过渡金属中,变形结合是常见的,但在散装 (W) 和 (Mo) 中通常不会观察到.
- 在室温压缩下,W和Mo纳米晶体出乎意料地表现出双胞胎,挑战现有的核化理论.
研究的目的:
- 为了阐明在W和Mo纳米晶体中变形结合的物理起源.
- 调查压力应力和堆叠断层能量的作用,使结合成为可能.
主要方法:
- 密度函数理论 (DFT) 计算以计算压力依赖的一般化堆叠故障热量 (GSFH).
- 减少约束滑动方法来分析热力学稳定性.
- 直接进行原子学模拟,观察双胞胎生长途径.
主要成果:
- 压缩应力稳定了W和Mo的两层双胞胎胚胎.
- 双胞胎分离允许双胞胎胚胎快速生长,能量障碍最小.
- 原子模拟证实了DFT的预测,揭示了一个明确的生路径.
结论:
- 变形结是W和Mo在合剪切和高压力压力下首选的机制.
- 双性与堆叠故障阶段 (SFP) 的弹性常数相关,六角密封 (hcp) 阶段作为bcc金属的潜在SFP候选者.
相关概念视频
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