Ab initio study of the elastic properties of body-centered cubic Ti-Mo-based alloys

• Published in: Computational materials science 2020-02, Vol.172, p.109320, Article 109320
• Main Authors: Yang, Yaochun, Zhang, Hualei, Sun, Qiaoyan, Hu, Qing-Miao, Ding, Xiangdong, Wang, Yunzhi, Vitos, Levente
• Format: Article
• Language: English
• Subjects: Alloy design; Elastic properties; EMTO-CPA; First-principles calculations; Single-crystal Young's modulus; Ti alloys
• ISSN: 0927-0256; 1879-0801; 1879-0801
• DOI: 10.1016/j.commatsci.2019.109320

Ab initio calculations on the single-crystal elastic constants (Cij), Zener anisotropy ratio (C44/C′), and single-crystal Young’s moduli (E[hkl]) for bcc Ti-Mo-M (M = Mg, Mn, Ni, Zr, Nb, and W) ternary solid solutions as a function of Mo and M contents. [Display omitted] •The theoretical elastic moduli of Ti-Mo agree with the available calculated and experimental data.•Complex alloying effects are found in the lattice constants and elastic properties.•Mn, Ni, Nb, Zr, and W enhance both the Young’s modulus and the stability of the β phase.•The single crystal Young’s moduli of the Ti-Mo-based alloys show a strong elastic anisotropy. Using ab initio alloy theory, we systemically investigate the effect of alloying elements on the elastic properties of body-centered cubic (bcc) Ti1−x−yMoxMy (0.05 ≤ x ≤ 0.2; 0 ≤ y ≤ 0.4; M = Mg, Mn, Ni, Zr, Nb, and W) alloys. The theoretical single-crystal and polycrystalline elastic moduli of Ti1−xMox (0.05 ≤ x ≤ 0.2) agree well with the available experimental values and previous theoretical data. The lattice parameters of Ti-Mo-M ternary alloys significantly increase (decrease) with increasing Mg and Zr (Mn and Ni) contents, while remain almost constant for Nb and W additions. It is found that Mg is a promising alloying element that could decrease the Young’s modulus of bcc Ti-Mo alloys, but its content should be as small as possible since the stability of the β phase decreases with increasing Mg concentration. On the other hand, Mn, Ni, Nb, Zr, and W enhance the Young’s modulus and the stability of the β phase.