Temperature-dependent hardness of zinc-blende structured covalent materials  

闪锌矿结构共价材料的高温硬度

作　　者：Xing Feng Jianwei Xiao Bin Wen Jijun Zhao Bo Xu Yanbin Wang Yongjun Tian 冯幸;肖建伟;温斌;赵纪军;徐波;王雁宾;田永君(Center for High Pressure Science,State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China;Key Laboratory of Materials Modification by Laser,Ion and Electron Beams(Ministry of Education),Dalian University of Technology,Dalian 116024,China;Center for Advanced Radiation Sources,University of Chicago,Chicago,Illinois 60439,USA)

机构地区：[1]Center for High Pressure Science,State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China [2]Key Laboratory of Materials Modification by Laser,Ion and Electron Beams(Ministry of Education),Dalian University of Technology,Dalian 116024,China [3]Center for Advanced Radiation Sources,University of Chicago,Chicago,Illinois 60439,USA

出　　处：《Science China Materials》2021年第9期2280-2288,共9页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China (51925105, 51771165, and 51525205);the National Magnetic Confinement Fusion Energy Research Project of China (2015GB118001);the US National Science Foundation (NSF,EAR-1361276);the National Key R&D Program of China(YS2018YFA070119)

摘　　要：Understanding the temperature-dependent hardness of covalent materials is of fundamental scientific interest and crucial technical importance.Here we propose a temperature-dependent hardness formula for zinc-blende structured covalent materials based on the dislocation theory.Our results indicate that at low temperatures,the Vickers hardness is primarily modulated by Poisson’s ratio and the shear modulus,with the latter playing a dominant role.With an increase in temperature,the governing mechanism for the plastic deformation switches from shuffle-set dislocation control to glide-set dislocation control,and the hardness decreases precipitously at elevated temperatures.Moreover,the intrinsic parameter a3G is revealed for zinc-blende structured covalent materials,which represents the resistance of a material to softening at high temperatures.This temperaturedependent hardness model agrees remarkably well with the experimental data of zinc-blende structured covalent materials.This work not only sheds light on the physical origin of hardness,but also provides a practical guide for the design of superhard materials.共价材料高温硬度的研究,不仅具有基本的科学意义,而且具有非常重要的应用价值.基于位错理论,本文提出了一个针对闪锌矿结构共价材料高温维氏硬度的理论模型.在忽略温度效应时,硬度仅与泊松比和剪切模量有关,且剪切模量的影响较大.随温度升高,硬度下降,当大于某一临界温度时,其下降趋势陡然增加,该下降趋势的突变主要来源于控制位错滑移的位错由拖拉面位错向滑移面位错转变.研究结果还表明,材料本征参数a3G可以用来表征材料抗升温软化的能力.此外,本研究的计算结果与实验结果很好吻合.本研究不仅可以解释硬度的物理本质,也可为超硬材料的设计提供指导.

关 键 词：HARDNESS temperature effect DISLOCATION covalent materials superhard materials 

分 类 号：TB34[一般工业技术—材料科学与工程]