First-principles Determinations of Geometric Structure and Stability of α Phase in Binary Ti-xM (M=V,Nb,Mo and Ta) Alloys
β-titanium alloys such as Ti-V,Ti-Nb,Ti-Mo,Ti-Ta,etc.,exhibit shape memory effect and pseudo-elasticity due to the thermally and mechanically reversible martensitic transition between α and β phases. The geometric structure and stability (relative to β) of the α phase are crucial to the understanding of these interesting properties. By the use of first-principles exact muffin-tin orbital method in combination with coherent potential approximation, the geometric structure and relative stability of a phase in binary TixM (M=V,Nb,Mo,Ta) alloys against the composition x are investigated in this paper. It is shown that the geometric structure of α phase is highly composition dependent; with increasing x.the lattice parameters b/a and c/a as well as the shift of the atomic position y decrease from those of the α phase to those of the β phase. The α-α and βα phase transitions occur without energy barrier. The calculated α/α composition phase boundaries are in good agreement with experiments. However, the β/α phase boundaries are significantly overestimated. We ascribe this discrepancy to the lattice vibration effect at finite temperature.
First-principles calculations β-Ti alloys phase stability crystal structure martensitic transformation
Chun-Xia Li Qing-Miao Hu Fu-Xing Yin Osamu Umezawa Rui Yang
Department of Materials Science and Engineering,Yokohama National University,Tokvwadai 79-5,Hodogaya Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sc Metallurgical Processing Group,National Institute for Materials Science,Tsukuba 305-0047,Japan Department of Materials Science and Engineering,Yokohama National University,Tokvwadai 79-5,Hodogaya
国际会议
The 12th World Conference Titanium(第十二届世界钛会 Ti-2011)
北京
英文
2121-2125
2011-06-19（万方平台首次上网日期，不代表论文的发表时间）