在以身体为中心的立方螺杆位移芯中空隙解离
1Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899.
概括
分子动力学模拟显示,BCC金属中螺丝脱位附近的空隙可以沿着脱位线分离. 这种以前未知的行为,由大多数潜能预测,可能会影响脱位固定和扩散.
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:
- 螺丝的脱位和空隙是体中心立方体 (BCC) 金属的关键缺陷.
- 了解它们的相互作用对于预测材料特性和性能至关重要.
- 经典的原子间潜力被广泛用于建模这些相互作用.
研究的目的:
- 为了研究螺杆位移和BCC金属中空隙之间的相互作用.
- 用各种经典的原子间潜能来评估与空位,位移及其相互作用相关的材料特性.
- 在这种交互过程中识别和描述新的行为.
主要方法:
- 使用了分子动力学 (MD) 模拟.
- 使用了13个经典的原子间电位:铁6个,2个,5个.
- 潜力包括嵌入式原子方法 (EAM),修改式嵌入式原子方法 (MEAM) 和角度依赖潜力 (ADP) 风格.
主要成果:
- 观察到一种以前未被识别的行为:沿着脱位线的空位分离.
- 十三种潜能中的十种预测了这种分离,空缺不再作为离散点缺陷.
- 发现空缺分离的具体结构是潜在依赖的,并在本研究中进行了表征.
结论:
- 沿螺杆脱位线的空隙解离是BCC金属中的一个重要现象.
- 这种解离改变了脱位核心结构.
- 它提出了一个潜在的新机制,用于位移钉定,并影响BCC金属中的管道扩散.
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