Study on structural,mechanical and thermodynamic properties of TiAl alloy under high pressure based on first-principles  

基于第一性原理的高压下TiAl结构、力学性能及热力学性质研究（英文）

作　　者：邓世杰[1] 赵宇宏[1] 文志勤 韩培德[2] 

机构地区：[1]中北大学材料科学与工程学院,山西太原030051 [2]太原理工大学材料科学与工程学院,山西太原030024

出　　处：《Journal of Measurement Science and Instrumentation》2017年第2期147-153,共7页测试科学与仪器（英文版）

基　　金：National Natural Science Foundation of China(Nos.U1610123,51674226,51574207,51574206,51274175);International Cooperation Project of the Ministry of Science and Technology of China(No.2014DFA50320);Science and Technology Major Project of Shanxi Province(No.MC2016-06);International Science and Technology Cooperation Project of Shanxi Province(No.2015081041);Research Project Supported by Shanxi Scholarship Council of China(No.2016-Key 2);Transformation of Scientific and Technological Achievements Special Guide Project of Shanxi Province(No.201604D131029)

摘　　要：The effect of pressure on structural, mechanical properties as well as the temperature dependence of thermodynamic properties of TiAl alloy are investigated by implementing first-principles calculations. The results show that the volume decrea-ses with the pressure increasing. We calculated the CtJ at various pressures and all the results satisfy mechanical stability crite-ria, thus the TiAl alloy is mechanically stable. The elastic constants？ bulk modulus and shear modulus calculated are well in a-greement with the calculated values at zero the pressure. The bulk modulus and shear modulus increase with the pressure in-creasing, which reflects the deformation resistance, and accordingly, deformation resistance can be strengthened with the in-crease of pressure. The brittle nature of TiAl alloy turns to ductile nature in 10 - 20 GPa . The Debye temperature, linear ther-mal expansion and heat capacity are calculated using the quasi-harmonic Debye model under the pressure ranging from 0 to 50 GPa and the temperature ranging from 0 to 1 000 K, which are useful to investigate the effect of temperature and pressure on thermodynamic parameters. Finally, electronic structure is calculated at various pressures,and it can be found that the peak intensity decreases with increasing pressure and the the strength of d-d orbital of Ti is weakened but the ductility is enhanced.

关 键 词：TiAl alloy FIRST-PRINCIPLES crystal structure elastic properties thermodynamic properties electronic structure 

分 类 号：TG146.23[一般工业技术—材料科学与工程]