在温度梯度下BCC谷粒边界的迁移机制:从分子动态对结构差异和热效应的洞察力
Zhuolun Wang1, Engui Leng1,2, Hengjun Luo3
1School of Materials Science & Engineering, Sichuan University, Chengdu, P. R. China.
Journal of molecular modeling
|December 11, 2025
概括
温度梯度驱动瓦纳中的谷物边界迁移,受边界结构和温度的影响. 分子动力学模拟揭示了在不同温度下不同的迁移机制,影响材料特性.
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:
- 温度梯度通过推动谷物边界迁移,显著影响材料加工和高温应用.
- 的高点允许在广泛的温度梯度范围内进行模拟,而无需相位变化,从而促进集中研究.
- 了解热应力下的谷物边界迁移对于预测和控制材料特性至关重要.
研究的目的:
- 在温度梯度驱动力下研究瓦纳中不同粒度边界类型的原子重新排列和迁移行为.
- 阐明谷物边界结构和温度对的迁移速率的影响.
- 通过控制的谷物边界迁移,为优化微观结构和机械性能提供理论基础.
主要方法:
- 利用使用LAMMPS软件和嵌入式原子方法 (EAM) 潜力的分子动力学 (MD) 模拟.
- 构建了具有各种粒度边界类型 (例如, Σ5, Σ31a) 的二晶模型.
- 应用了温度梯度 (500-1100 K和600-1600 K),并使用OVITO可视化软件分析了结构动态和迁移.
主要成果:
- 谷物边界结构显著影响了低于扰乱过渡温度 (~0.5-0.7 Tm) 的迁移速度.
- 低误导边界显示出位位滑动 (1/2<111>螺杆位位),而高误导边界显示出协调的原子运动.
- 在扰乱过渡温度以上,局部扰乱,多余的自由体积和空隙促进了集体原子运动和扩散,由谷物边界粗增强.
结论:
- 瓦纳的粒度边界迁移是一个取决于温度的过程,涉及多个协同作用的机制.
- 该研究提供了对温度梯度,谷物边界结构和原子移动性之间的相互作用的基本见解.
- 这些发现为在苛刻的热环境中定制的微观结构和机械性能提供了理论基础.
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