First-principles modeling of hardness in transition-metal diborides

被引：54

作者：

Lazar, Petr ^{[1
]}

Chen, Xing-Qiu ^{[1
]}

Podloucky, Raimund ^{[1
]}

机构：

[1] Univ Vienna, Inst Phys Chem, A-1090 Vienna, Austria

来源：

PHYSICAL REVIEW B | 2009年 / 80卷 / 01期

关键词：

ab initio calculations; density functional theory; dislocations; elasticity; fracture; hafnium compounds; iridium compounds; microhardness; osmium compounds; rhenium compounds; shear strength; stress effects; tantalum compounds; tungsten compounds; SUPERHARD RHENIUM DIBORIDE; HIGH-TEMPERATURE HARDNESS; AUGMENTED-WAVE METHOD; OSMIUM DIBORIDE; STACKING FAULTS; CRYSTALS; ENERGY; OSB2;

D O I：

10.1103/PhysRevB.80.012103

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Based on recent experiments, the diborides OsB2 and ReB2 were proposed to be ultraincompressible and superhard materials. By application of an ab initio density-functional theory approach we investigate the elastic and cleavage fracture properties of the borides MB2 (M= Hf, Ta, W, Re, Os, and Ir). We derive a direct correlation between the lowest calculated critical cleavage stress and the experimental (micro)hardness. By calculating the critical shear stress and estimating the possibility of dislocation emission we can justify the prediction that ReB2 is indeed a superhard material.

引用

页数：4

共 32 条

[1] PROJECTOR AUGMENTED-WAVE METHOD [J].