J. Mater. Sci. Technol. ›› 2021, Vol. 90: 168-182.DOI: 10.1016/j.jmst.2020.12.085

• Research Article • Previous Articles     Next Articles

Phase field simulation of the stress-induced α microstructure in Ti-6Al-4 V alloy and its CPFEM properties evaluation

Jinhu Zhanga,b,*(), Xuexiong Lia,b, Dongsheng Xua,b,d,*(), Chunyu Tengc, Hao Wanga,b, Liang Yanga,b, Hongtao Jua,b,d, Haisheng Xua,b,d, Zhichao Menga,b,d, Yingjie Maa,b,d, Yunzhi Wange, Rui Yanga,b,d   

  1. aInstitute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
    bShi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
    cChina Aero-Polytechnology Establishment, Beijing 100028, China
    dSchool of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
    eDepartment of Materials Science and Engineering, The Ohio State University, 2041 Collesnited States
  • Received:2020-11-06 Revised:2020-12-09 Accepted:2020-12-21 Published:2021-11-05 Online:2021-11-05
  • Contact: Jinhu Zhang,Dongsheng Xu
  • About author:dsxu@imr.ac.cn (D. Xu).
    * Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China. E-mail addresses: jinhuzhang@imr.ac.cn (J. Zhang),

Abstract:

Variant selection under specific applied stresses during precipitation of α plates from prior-β matrix in Ti-6Al-4 V was investigated by 3D phase field simulations. The model incorporates the Burgers transformation path from β to α phase, with consideration of interfacial energy anisotropy, externally applied stresses and elastic interactions among α variants and β matrix. The Gibbs free energy and atomic mobility data are taken from available thermodynamic and kinetic databases. It was found that external stresses have a profound influence on variant selection, and the selection has a sensitive dependence, as evidenced by both interaction energy calculations and phase field simulations. Compared with normal stresses, shear stresses applied in certain directions were found more effective in accelerating the transformation, with a stronger preference to fewer variants. The volume fractions of various α variants and the final microstructure were determined by both the external stress and the elastic interaction among different variants. The α clusters formed by variants with Type2 misorientation ([1 1 -2 0]/60°) relation were found more favored than those with Type4 ([-10 5 5 -3]/63.26°) under certain applied tensile stress such as along <111>β. The mechanical properties of different microstructures from our phase field simulation under different conditions were calculated for different loading conditions, utilizing crystal plastic finite element simulation. The mechanical behavior of the various microstructures from phase field simulation can be evaluated well before the alloys are fabricated, and therefore it is possible to select microstructure for optimizing the mechanical properties of the alloy through thermomechanical processing based on the two types of simulations.

Key words: Titanium alloy, Phase transformation, Microtexture, Mechanical evaluation, Phase field, Crystal plasticity finite element