J. Mater. Sci. Technol. ›› 2021, Vol. 74: 78-88.DOI: 10.1016/j.jmst.2020.10.013

• Research Article • Previous Articles     Next Articles

Designing high-strength titanium alloy using pseudo-spinodal mechanism through diffusion multiple experiment and CALPHAD calculation

Di Wua,b,c, Libin Liua,b, Lijun Zenga,b, Wenguang Zhud, Wanlin Wangc, Xiaoyong Zhanga,*(), Junfeng Houe,*(), Baoliang Liuf, Jiafeng Leig, Kechao Zhoua,b   

  1. a State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
    b School of Material Science and Engineering, Central South University, Changsha 410083, China
    c School of Metallurgy and Environment, Central South University, Changsha 410083, China
    d School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China
    e School of Materials Science & Engineering, North Minzu University, Yinchuan 750021, China
    f Xi’an Trianlge Defence Incorporated Company, Xi’an, 710089, China
    g Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:2020-07-12 Revised:2020-08-31 Accepted:2020-09-07 Published:2020-10-08 Online:2020-10-08
  • Contact: Xiaoyong Zhang,Junfeng Hou
  • About author:hou8635@yeah.net (J. Hou).
    *E-mail addresses: zhangxiaoyong@csu.edu.cn (X. Zhang),


This study used the pseudo-spinodal mechanism to obtain the ultrafine α phase for designing high-strength titanium alloy. Diffusion multiple experiments were designed to find the composition range of TM-xMo-yV alloy (TM: Ti-4.5Al-2Cr-2.5Nb-2Zr-1Sn) for obtaining ultrafine α phase. CALPHAD results confirm that when the alloy composition is located near the intersection of the α and β phase free energy curves, the alloy will undergo pseudo-spinodal transformation and obtain the ultrafine α phase. The designed TM-6Mo-3V alloy has a yield strength of 1411 MPa and an elongation of 6.5 %. The strength of the alloy depends on the thickness, fraction of the α phase and the solid solution strengthening effect of the alloying elements. The deformation mechanism of the alloy is the dislocation slip of the α and β phases and the twin deformation of the α phase. The large number of α/β interfaces produced by the fine α phase is the main reason for limiting the ductility of the alloy. The use of the pseudo-spinodal mechanism combined with diffusion multiple experiments and CALPHAD is an effective method for designing high-strength titanium alloys.

Key words: Pseudo-spinodal mechanism, Alloy design, CALPHAD, Diffusion multiple, Strengthening mechanism