Cyclic Plastic Deformation Behavior of TC4 Titanium Alloy Under Different Microstructures and Load Conditions Using Finite Element Method

This paper focuses on the plastic deformation behavior of TC4 titanium alloy under cyclic loading by the finite element method. Finite element models were established based on the realistic microstructure whose volume fraction and gain size of primary α phase are 11.86% and 10.35 μm, respectively. The effect of cyclic loading conditions and microstructure characteristics on cyclic plastic deformation behavior of the alloy was analyzed. The results showed that due to the obvious difference in mechanical properties between primary α phase and transformed β matrix, their equivalent plastic strains are obviously different after different cycles of cyclic loading. Moreover, the equivalent plastic strain gradually decreases with the increase in primary α phase volume fraction, the decrease in primary α phase grain size, the decrease in strain amplitude and the increase in strain ratio, respectively. There is a close relationship between plastic damage and fatigue strength of the metal materials. The cyclic loading conditions and microstructure characteristics have a great influence on the fatigue life of TC4 titanium alloy.