Anisotropic behavior and constitutive equations of superplastic deformation of a Ti-6Al-4V alloy

The anisotropic behavior and constitutive equations of the superplastic deformation of a Ti-6Al-4V alloy were examined. The `circular-to-elliptical' cross section change in superplastic tensile and compression deformation was mainly due to the microstructure. The anisotropic factor, R, was almost constant when the strain-induced microstructural changes was negligible. As the strain rate increased, R-value increased towards 1 and the σ-ε curves of different types of specimens machined from the same material converged.