Effect of Nb on the Properties of Ti-Nb Random Alloys from First-principles

摘要：

　　The effect of Nb on the equilibrium lattice parameters and relative stability between β and ω phases of Ti1-xNbx (0 < x ≤ 0.4) random alloys as well as their mechanical properties in body-centered-cubic crystallographic phase was investigated using the exact muffin-tin orbitals method in combination with the coherent potential approximation.It has been found that the calculated lattice parameters of the β phase agree well with the experimental data.For ω phase,the value of a increases almost linearly with increasing Nb concentration,while the opposite situation presented for c/a.Both Nb addition and increasing temperature enhanced the stability of β phase relative to ω phase.The critical Nb concentration for the complete stabilization of β phase at 300 K,673 K and 1273 K was 22 at.%,17 at.% and 9 at.%,respectively.The polycrystalline bulk modulus B,Youngs modulus E and shear modulus G increased monotonously with Nb addition and reducing the Nb concentration below 30 at.%resulted in lower E compared to that of Ti-6Al-4V.The calculated G/B values demonstrate that the bcc Ti1-xNbx (0 < x ≤ 0.4) random alloys should be intrinsically ductile.

关键词： Ti-Nb First principles Phase stability Mechanical properties

作者: Minjie Lai Xiangyi Xue Caisi Meng Hongchao Kou Bing Tang Hui Chang Jinshan Li

作者单位: State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, China

会议类型: 国际会议

会议名称: the Chinese Materials Congress 2012(2012年中国材料大会(CMC2012))

会议地点: 太原

会议语种:英文

页码: 890-898

在线出版日期: 2012-07-13（万方平台首次上网日期，不代表论文的发表时间）