厦门大学学报（自然科学版）2017，Vol.56Issue(2)：156-165,10.DOI:10.6043/j.issn.0438-0479.201604042
L12结构γ′-Co3(Al1-xWx)相的弹性性质和热力学性质的第一性原理研究
First-principles Study of Elastic Properties and Thermodynamic Properties of L12 Ordered γ′-Co3(Al1-xWx)
摘要
Abstract
The effects of W concentration on the elastic properties,and thermodynamic properties of γ′-Co3(Al1-xWx) (x=0,0.25,0.50,0.75,1.0)are investigated using first-principles calculations within generalized gradient approximation (GGA).It is found that the elastic modulus of γ′-Co3(Al1-xWx),including bulk modulus,shear modulus and Young′s modulus,increase with increasing W concentration,while the degree of elastic anisotropy decreases with increasing W concentration.In addition,γ′-Co3(Al1-xWx) experiences a ductile-to-brittle transition as the W concentration is increased.By analyzing the charge density distribution and the density of states,it is found that the directional bonding between Co atoms and W atoms becomes stronger with increasing W concentration,and the electron density between Co atoms tends to distribute in a more isotropic manner with increasing W concentration.Moreover,based on the quasi-harmonic Debye-Gruneisen approach,the thermodynamic properties as a function of temperature of γ′-Co3(Al1-xWx)(x=0,0.25,0.50,0.75,1.0)are calculated,including heat capacities,entropy,enthalpy and thermal expansion coefficients.It was found that heat capacities,enthalpy and thermal expansion coefficient decrease with increasing W concentration.关键词
第一性原理计算/Co基高温合金/弹性性质/热力学性质Key words
first-principles calculations/Co-base superalloys/elastic properties/thermodynamic properties分类
数理科学引用本文复制引用
刘兴军,邓斌,许伟伟,韩佳甲,王翠萍..L12结构γ′-Co3(Al1-xWx)相的弹性性质和热力学性质的第一性原理研究[J].厦门大学学报（自然科学版）,2017,56(2):156-165,10.基金项目
国家国际科技合作专项(2014DFA53040) （2014DFA53040）
