Enhanced fracture toughness of boron carbide from microalloying and nanotwinning
Enhanced fracture toughness of boron carbide from microalloying and nanotwinning
复制标题
微合金化和纳米孪晶对碳化硼断裂韧性的提高
DOI：
10.1016/j.scriptamat.2018.11.035
复制
发表时间：
2019-03
影响因子：
6
通讯作者：
Yidi Shen;Guodong Li;Q. An
中科院分区：
文献类型：
--
作者：
Yidi Shen;Guodong Li;Q. An
断裂韧性是结构材料最重要的力学性能之一。特别是，提高超硬材料的断裂韧性是其应用的必要条件。本文应用密度泛函理论研究了微合金化和纳米孪晶对超硬碳化硼（B4 C）断裂韧性的影响。我们发现用双原子链特别是弱耦合的氧原子取代C-B-C链可以显著提高B4 C的断裂韧性。此外，插入纳米孪晶可以显着提高B4 C和硼相的断裂韧性。研究结果为设计具有高断裂韧性的硼基超硬材料提供了有用的信息。
Fracture toughness is one of the most important mechanical properties of structural materials. Particularly, enhancing the fracture toughness of super-hard materials is essential for their applications. Here, we applied density functional theory to examine how the microalloying and nanotwinning affect the fracture toughness of superhard boron carbide (B4C). We find that replacing C-B-C chains with two-atom chains especially weakly coupled O atoms can significantly improve the fracture toughness of B4C. In addition, inserting nanotwins can significantly enhance the fracture toughness of B4C and boron phases. Our results provide useful information to design boron based superhard materials with enhanced fracture toughness.