金属学报  2019, Vol. 55 Issue (7): 928-938    DOI: 10.11900/0412.1961.2018.00380
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1. 中国科学院金属研究所 沈阳 110016
2. 中国科学院大学 北京 100049
Crystal Plasticity Finite Element Method Investigation of the High Temperature Deformation Consistency in Dual-Phase Titanium Alloy
Xuexiong LI1,2,Dongsheng XU1(),Rui YANG1
1. Institute of Metal Research, Chinese Academy of Science, Shenyang 110016, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
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Abstract

Based on the rate-dependent crystal plasticity constitutive model considering all slip systems, a series of dual-phase polycrystalline models were established using 3D Voronoi tessellation to investigate the high temperature plastic deformation of Ti-6Al-4V alloy with different microstructure features. The spatial distributions and evolution of stress and strain in various grains and phases were calculated in detail, and a new method was proposed to evaluate quantitatively the deformation consistency in the alloy with two phases. Simulations show that grain boundary region responds preferentially in the early stage of deformation. The encircling structure formed between β and α grains can enhance the differences in the local strain distribution. Increasing the aspect ratio of grains and the fractions of heterogeneous phase interface can reduce the local compatibility of deformation. The stress frequency statistics of both α and β phases show a double peak form, with α phase higher in average strain, and β phase higher in stress distribution. Increasing of the volume fractions of α phase may reduce the tensile yield strength, and cause the stress consistency coefficient to decrease, while the strain consistency coefficient decreases first and then increases. As initial α-basal texture intensity increases, both tensile yield strength and stress consistency coefficient increase, while the strain consistency coefficient decreases first and then increases.

Key wordsdual-phase titanium alloy    Voronoi    crystal plasticity finite element method (CPFEM)    distribution of micro stress and strain    deformation compatibility

 ZTFLH: TG113.25

Corresponding author: Dongsheng XU     E-mail: dsxu@imr.ac.cn