奥斯二化物是一种超硬材料吗?
Jun Yang1, Hong Sun, Changfeng Chen
1Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, China.
Journal of the American Chemical Society
|May 16, 2008
概括
第一个原则的计算显示,OsB2表现出异构的剪切强度. 它对 (001) [100] 剪切的高阻力有助于其超硬性,但弱 (001) [010] 剪切限制了一些应用.
科学领域:
- 材料科学 材料科学 材料科学
- 计算材料科学科学 计算材料科学
- 固态物理 固态物理
背景情况:
- 奥二化物 (OsB2) 代表了一类新的超硬材料.
- 这些材料结合了轻质,共价元素和重过渡金属.
- 了解变形机制对于设计新型硬材料至关重要.
研究的目的:
- 为了研究Orthorhombic OsB2.2的理想拉力和剪切强度.
- 阐明控制其机械性能的原子变形模式.
- 为了将计算的强度与实验硬度观测相关联.
主要方法:
- 使用第一原则计算来模拟机械行为.
- 拉力和剪切强度的计算是在正弦形的OsB2结构上进行的.
- 在不同的晶体学方向上分析了剪强度的异质性.
主要成果:
- 正方体OsB2在 (001) 平面上表现出高度异构的剪切强度.
- 与 (001) [010] 方向 (9.1 GPa) 相比, (001) [100] 方向 (26.9 GPa) 的峰值切割应力显著更高.
- 计算的强度与 (001) 平面上的30 GPa的实验维克尔硬度保持一致.
结论:
- 对 (001) [100] 剪切变形的强烈抵抗是OsB2高维克尔硬度的原因.
- 较弱的 (001) [010] 剪切强度限制了其在磨料和切割应用中的使用.
- 了解异型变形模式对于先进超硬材料的合理设计至关重要.
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