在金属玻璃中弹性极限的异常温度依赖性
Yifan Wang1, Jing Liu2, Jian-Zhong Jiang3,4
1Department of Mechanical Engineering, Stanford University, Stanford, CA, USA.
Nature communications
|January 3, 2024
概括
这项研究揭示了温度如何影响金属玻璃 (MGs) 的弹性极限. 温度的升高可以通过使剪切转换事件可逆,令人惊地提高弹性极限.
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:
- 由于金属玻璃的无形结构,很难理解金属玻璃 (MGs) 的不弹性变形.
- 在MG中,局部可塑性载体不易被定义,这阻碍了机械学的理解.
研究的目的:
- 研究CuZr金属玻璃中不弹性变形的原子化机制.
- 分析弹性极限的温度依赖性及其与剪切转换 (ST) 事件的关系.
主要方法:
- 使用分子动力学 (MD) 模拟来建模变形.
- 从ST能源障碍的高通量计算构建一个能量应变景观 (ESL).
主要成果:
- 剪切转换 (ST) 事件始于温度上升的较低菌株.
- 在特定范围内观察到弹性极限随温度的异常增加.
- 能量应变景观 (ESL) 通过ST事件的过渡来解释这种异常,即随着温度的增加,ST事件从不可逆转变为可逆转.
结论:
- 温度诱导的从不可逆转到可逆的剪切转换事件的过渡控制了金属玻璃中的异常弹性极限行为.
- 开发了一个分析模型来预测这种过渡和温度依赖的弹性极限.
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