Effect of Mn doping on mechanical properties and electronic structure of WCoB ternary boride by first-principles calculations  

作　　者：Tong Zhang Hai-Qing Yin Cong Zhang Xuan-Hui Qu Qing-Jun Zheng 张桐;尹海清;张聪;曲选辉;郑清军(Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing,Beijing 100083,China;Beijing Key Laboratory of Materials Genome Initiative,University of Science and Technology Beijing,Beijing 100083,China;Kennametal Inc,1600 Technology Way,PA 15650,USA)

机构地区：[1]Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, China [2]Beijing Key Laboratory of Materials Genome Initiative, University of Science and Technology Beijing, Beijing 100083, China [3]Kennametal Inc, 1600 Technology Way, PA 15650, USA

出　　处：《Chinese Physics B》2018年第10期537-547,共11页中国物理B（英文版）

基　　金：Project supported by the National Key Research and Development Program,China(Grant No.2016YFB0700503);the National High Technology Research and Development Program of China(Grant No.2015AA034201);the Beijing Science and Technology Plan,China(Grant No.D161100002416001);the National Natural Science Foundation of China(Grant No.51172018);the Kennametal Inc.,China

摘　　要：The first-principles calculations are performed to investigate the structural, mechanical property, hardness, and electronic structure of WCoB with 0, 8.33, 16.67, 25, and 33.33 at.% Mn doping content and W_2 CoB_2 with 0, 10, and 20 at.%Mn doping content. The cohesive energy and formation energy indicate that all the structures can retain good structural stability. According to the calculated elastic constants, Mn is responsible for the increase of ductility and Poisson＇s ratio and the decrease of Young＇s modulus, shear modulus, and bulk modulus. By using the population analysis and mechanical properties, the hardness is characterized through using the five hardness models and is found to decrease with the Mn doping content increasing. The calculated electronic structure indicates that the formation of a B–Mn covalent bond and a W–Mn metallic bond contribute to the decreasing of the mechanical properties.The first-principles calculations are performed to investigate the structural, mechanical property, hardness, and electronic structure of WCoB with 0, 8.33, 16.67, 25, and 33.33 at.% Mn doping content and W_2 CoB_2 with 0, 10, and 20 at.%Mn doping content. The cohesive energy and formation energy indicate that all the structures can retain good structural stability. According to the calculated elastic constants, Mn is responsible for the increase of ductility and Poisson＇s ratio and the decrease of Young＇s modulus, shear modulus, and bulk modulus. By using the population analysis and mechanical properties, the hardness is characterized through using the five hardness models and is found to decrease with the Mn doping content increasing. The calculated electronic structure indicates that the formation of a B–Mn covalent bond and a W–Mn metallic bond contribute to the decreasing of the mechanical properties.

关 键 词：Mn doping WCoB electronic structure first-principles calculations 

分 类 号：TG135.5[一般工业技术—材料科学与工程]