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纳米结构立方化的可塑性机制:内部缺陷和无形层
Ao Geng1,2, Zhaorui Liu1,2, Tengfei Xu1,2
1School of Materials Science and Engineering, Beihang University, Beijing 100191, P. R. China.
ACS applied materials & interfaces
|September 8, 2025
概括
研究人员开发了一种策略,通过设计内部缺陷和无形接口层 (AILs) 来增强纳米结构立方化 (NS-cBN) 的强度和性. 这种方法为创建具有改进机械性能的先进超硬材料提供了一条途径.
科学领域:
- 材料科学与工程 材料科学与工程
- 纳米技术 纳米技术
- 计算材料科学科学 计算材料科学
背景情况:
- 纳米结构立方化 (NS-cBN) 具有高硬度和热稳定性.
- 需要一个系统的方法来通过结构设计平衡NS-cBN的强度和性.
- 了解诸如双边界 (TBs),堆叠断层 (SFs),脱位网络和无形界面层 (AILs) 等缺陷的作用至关重要.
研究的目的:
- 阐明NS-cBN中各种内部缺陷和AIL的尺寸依赖作用.
- 建立NS-cBN中平衡强度和性的设计原则.
- 引导下一代超硬材料的开发.
主要方法:
- 整合可塑性理论与大规模的原子学模拟.
- 缺陷机制的分析,包括脱位透,谷物边界滑动和断裂机制的脱节.
- 研究AIL厚度,密度和粘合强度对机械性能的影响.
主要成果:
- 滑动模式和谷物边界滑动之间的竞争决定了TB和SF中的强度和裂纹启动应变.
- 错位的交叉滑动和分离断裂机制增强了强度和性.
- 脱位网络增加了76%的故障应变,并诱导了类似金属的塑料高原.
- 一个0.5纳米厚的AIL同时通过同质化应力和抑制裂纹的启动来增强强度和性.
结论:
- 对内部缺陷和AIL的协同定制可以实现NS-cBN,其结合的高强度和性.
- 制定了用于开发先进超硬材料的一般设计原则.
- 原子结构设计是优化NS-cBN机械性能的关键.
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