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采用超级胞和广义梯度近似条件下投影缀加平面波的第一性原理方法研究了β相Ti-X(X=Nb,Mo)合金结构稳定、弹性性能及其电子结构,并利用Voigt-Reuss-Hill平均方法从单晶Ti-X合金的弹性常数计算出了其多晶合金的弹性模量。研究结果表明,β型Ti-Nb和Ti-Mo合金的β结构稳定性随着Nb,Mo和Ta含量的增加而增加,当Nb或Mo含量为25at%时,Ti-Nb和Ti-Mo合金表现出最低的弹性模量。进一步,利用计算出的Ti-X合金的电子态密度(DOS)分析讨论了Nb和Mo合金元素含量对这2种合金结构稳定性的影响机理。
The stability and elastic properties of β-phase Ti-X (X = Nb, Mo) alloy and its electronic structure were studied by the first-principle method of projection-fitted plane wave projection under the condition of generalized gradient approximation and generalized gradient approximation. Voigt-Reuss- Hill Average Method The elastic modulus of a polycrystalline alloy was calculated from the elastic constants of the single crystal Ti-X alloy. The results show that the β-structure stability of β-type Ti-Nb and Ti-Mo alloys increases with the increase of Nb, Mo and Ta contents. When Nb or Mo content is 25at%, the structure of Ti-Nb and Ti-Mo alloys Show the lowest elastic modulus. Further, the influence mechanism of the contents of Nb and Mo alloying elements on the structural stability of the two alloys was discussed by using the calculated DOS of the Ti-X alloy.