首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Softest elastic mode governs materials hardness
Authors:Rong Yu  Qi Zhang  Qian Zhan
Institution:1. Beijing National Center for Electron Microscopy and Key Laboratory of Advanced Materials of Ministry of Education of China, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
2. School of Material Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
Abstract:Single-crystal elastic constants and mechanical hardness of covalent and ionic crystals have been studied using first-principles calculations. The results show that the hardness is dominated by the softest elastic mode, not by the averaged elastic moduli as generally assumed. It reveals that the mechanical stability and anisotropy play an important role in determining the hardness of materials. The concept is then employed in designing hard alloys. By strengthening the softest elastic mode of tungsten carbide, which is the primary component in industrial hard alloys, we show that the carbide can be made even harder by alloying with nitrogen or rhenium via Fermi-level tuning.
Keywords:Hardness  Elastic constants  Elastic eigenmodes  Anisotropy
本文献已被 CNKI 维普 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号