中文摘要：

基于第一原理赝势平面波方法和虚拟晶体势函数近似(VCA),提出了一种计算Ti-Al-Nb合金V合金化的形成热和力学性能的方法和模型。计算结果表明:Ti-Al-Nb合金V合金化时V倾向占据O-Ti2AlNb晶体的Nb点阵位。合金化产物O-Ti-22Al-[Nb(27-x)Vx]晶体的弹性模量理论计算值与室温测量值非常接近,并通过计算预测了当V合金化浓度x在1%~3%变化时晶体的弹性模量逐渐降低。采用Pugh判据B/G和B/C44比值表征和评判了V合金化浓度对O-Ti-22Al-27Nb晶体延性的影响。计算表明:V合金化浓度为1%~2%时不能改善O-Ti-22Al-27Nb晶体的延性,但当V浓度为3%时能显著增加O-Ti-22Al-27Nb的延性。从理论数据和实验结果对比来看,这种计算Ti-Al-Nb合金V合金化的形成热和力学性能的模型和方法比较准确和可靠,在为实验结果提供理论支撑同时,还可对不同V合金化浓度的合金性能做出预测。

英文摘要：

Based on first-principle pseudo potential plane wave method and virtual crystal potential function approximation(VCA),a method and model on the calculation of formation heat and mechanical properties of Ti-Al-Nb alloy V s alloying was presented.The calculation results showed that Ti-Al-Nb alloy V tended to occupy the Nb crystal lattice spaces when it was alloyed.The calculated value of elastic modulus of alloying products(O-Ti-22Al-[Nb(27-x)Vx] crystal) was very close to the value measured at room temperatu...