桂林电子科技大学学报2011，Vol.31Issue(1)：68-73,6.
B2型Ti-Al-X合金相稳定性与力学性质的第一原理计算
First-principles calculation on the stability and mechanical properties of B2-Ti-Al-X alloys
摘要
Abstract
Using the first-principles pseudo-potential plane wave method, the electronic structures, energetics and the elastic moduli of B2-Ti-Al-X(X=Cr,Mo,Nb,W,Zr and Hr) crystals are calculated. The site preference of TM elements X in B2-TiAl crystal and the mechanical stability of these B2 phases with preferential site of X are also investigated by a comparison of the heats of formation and the Born Criterion of stability. The Cauchy pressures(C12-C44 )and the ratios of B/C44 have been adopted to characterize and assess the ductile/brittle behaviors of B2-Ti-Al-X phases. The results show Cr,Mo,Nb,Zr and W prefer to occupy Al sites in B2-TiAl crystal, and Hf mainly substitutes for Ti atoms. The ductility of B2-TiAl alloys with the addition of Cr,W or Zr is evidently improved relative to ΥTiAl alloys, whereas no toughening effect can be seen for the addition of Nb, Mo or Hf in B2-TiAl alloys.关键词
B2-TiAl/合金化/弹性性质/第一原理计算Key words
B2-TiAl/ alloying/ elastic property/ first-principles calculation分类
矿业与冶金引用本文复制引用
许密,曾宪波..B2型Ti-Al-X合金相稳定性与力学性质的第一原理计算[J].桂林电子科技大学学报,2011,31(1):68-73,6.基金项目
国家自然科学基金(50771044) （50771044）
国家重点基础研究发展规划项目(2006CB605104) （2006CB605104）
