Influence of Nb and Mo contents on phase stability and elastic property of β-type Ti-X alloys

来源期刊：中国有色金属学报(英文版)2007年第6期

论文作者：姚强 孙坚 邢辉 郭文渊

文章页码：1417 - 1421

Key words：Ti alloy; elastic property; phase stability; electronic structure; First-Principle

Abstract: The energetic, electronic structure and elastic property of β-type Ti_1-xX_x (X=Nb and Mo, x=0.041 7, 0.062 5, 0.125 0, 0.187 5, 0.250 0, 0.312 5 and 0.375) binary alloys were calculated by the method of supercell and augmented plane waves plus local orbitals within generalized gradient approximation. The elastic moduli of the polycrystals for these Ti_1-xX_x alloys were calculated from the elastic constants of the single crystal by the Voigt-Reuss-Hill averaging method. Based on the calculated results, the influence of X content on the phase stability and elastic property of β-type Ti_1-xx alloys was investigated. The results show that the phase stability, tetragonal shear constant C′, bulk modulus, elastic modulus and shear modulus of β-type Ti_1-xX_x alloys increase with an increase of X content monotonously. When the valence electron number of β-type Ti_1-xx alloys is around 4.10, i.e. the content of Nb is 9.87% (molar fraction) in the Ti-Nb alloy and Mo is 4.77% (molar fraction) in Ti-Mo alloy, the tetragonal shear constant is nearly zero. The Ti_1-xX_x alloys achieve low phase stability and low elastic modulus when the tetragonal shear constant reaches nearly zero. In addition, the phase stability of β-type Ti_1-xX_x alloys was discussed together with the calculated electronic structure.

基金信息：the Science and Technology Committee of Shanghai, China
the National Natural Science Foundation of China