Crystal Plasticity Simulation of the Effect of γ Lamellae on the Plastic Behavior of the Core–Shell-like Structured TiAl Alloy

The preparation of the core–shell-like structured before hot working can significantly enhance the hot workability of the alloy. In order to research the properties of the alloy, the finite element method combined with the crystal plasticity constitutive theory was used to establish the finite element model of the core–shell-like structured TiAl alloy with (α2 + γ) lamellae colonies as the core and α2 matrix as the shell. The research focuses on the influence of the length and number of γ lamellae on the stress–strain distribution and the contribution of slip systems in each phase to the plasticity of the alloy. The results show that when the γ lamella length increases from 12 μm to 16 μm, the overall stress decreases by 12.0%; when the number increases from 6 to 10, the stress decreases by 7.7%. The stress reduction is primarily influenced by the α2 phase. Increasing the volume fraction of γ lamellae facilitates stress distribution within the α2 phase and enhances the plasticity of the material. In the γ phase O4, S1 and S7 slip systems contribute the most to the plastic deformation of the γ phase. In the α2 phase, the B1 slip system is the main contributor to the plasticity of the α2 phase. And the B1 slip system contributes more significantly to the plastic deformation of the entire model.