Pressure-induced structure,electronic,thermodynamic and mechanical properties of Ti_(2)AlNb orthorhombic phase by first-principles calculations  

作　　者：Zhen-Yi Wei Kang-Ming Hu Bai-Sheng Sa Bo Wu 

机构地区：[1]Multiscale Computational Materials Facility,School of Materials Science and Engineering,Fuzhou University,Fuzhou 350100,China

出　　处：《Rare Metals》2021年第10期2964-2974,共11页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (Nos.50971043 and 51171046);the Research Fund for the Doctoral Program of Higher Education of China (No.20133514110006);the Natural Science Foundation of Fujian Province,China (No.2014J01176);the Program for New Century Excellent Talents in University of Fujian Province,China (No.JA10013)。

摘　　要：Effects of pressure on lattice parameters, electronic, thermodynamic and mechanical properties of the fully ordered Ti_(2)AlNb orthorhombic phase were studied using first-principles calculations based on density functional theory(DFT). The bonding nature for ordering orthorhombic Ti_(2)AlNb was revealed quantitatively through the electronic structure analyzing. The external pressures play limited roles in the elastic anisotropy of the alloy due to the outstanding dynamical and mechanical stabilities under pressure. However, the shear modulus of O phase manifests anisotropic, where {010} shear planes are the easiest planes to cleave among the principal planes under all pressures.The heat capacities, volume expansions and thermal expansion coefficients were calculated using the quasi-harmonic approximation model based on the phonon dispersion curves. Meanwhile, the bulk modulus, Young’s modulus,shear modulus and the hardness are promptly enhanced under pressure. The predicted results give hints to design Ti_(2)AlNb-based alloy as high-pressure applications.

关 键 词：Ti2AlNb-based orthorhombic phase Pressure-induced effect Thermodynamic properties Mechanical properties First-principles calculations 

分 类 号：TG146.23[一般工业技术—材料科学与工程]