Texture evolution prediction of diffusion bonded titanium alloy with hot gas bulging experiments by cross-scale simulation modeling

Developing a high precision cross-scale model for diffusion bonded (DB) titanium alloy to predict macroscopic deformation and microstructure evolution is critical for industrial production requirements. To characterize the plastic behaviors of DB TC4 alloy, the mechanical properties experiments were carried out under elevated temperatures. The gas bulging process of the alloy sheet was predicted, which was combined with the macroscopic finite element method (FEM) and crystal plasticity FEM, and the predicted mechanical behavior and texture evolution are in good agreement with the experimental results, and the relative errors between the two scales are generally minor. The effects of different strains and stress states on the microstructure heterogeneous deformation, crystal orientation, and slip mode of titanium alloy are discussed on this basis. The results indicate that more grains undergo significant plastic deformation from the stress states of plane strain to equal biaxial tension. The active rate of Prismatic slip decreases, and the Pyramidal slip systems also start obviously. The grains with easy-to-deform orientation can gradually rotate to a stable orientation during plastic deformation and have a lower Schmid factor.