B2型TiSi合金点缺陷结构和力学性能的第一性原理研究

摘要

Using a first-principle method base on density function theory, the lattice constant, formation energy, formation enthalpy and elastic properties are calculated for B2-TiSi alloy. The results show that Ti mono-vacancy (VTi) and Si anti-site (SiTi) defect are easier form in the alloy because of their smaller formation energy and formation enthalpy. Alloy defect structures have smaller bulk modulus and share modulus. Comparing to TiSi alloy, defect structures have a lower tenacity.%采用基于密度泛函理论的第一性原理计算了B2型TiSi合金各种点缺陷结构的晶格常数、形成能、形成热和弹性性质。结果表明：Ti空位缺陷(VTi)和Si反位缺陷(SiTi)的形成能和形成热较小，在合金过程中较易产生；合金缺陷结构具有小的体弹模量和剪切模量；相对TiSi合金完美结构，缺陷结构的韧性较低。