مهدی شبان غازانی

The strain-hardening behavior of materials is an important factor affecting the deformation homogeneity of the microstructure of samples after equal-channel angular pressing (Ecap). In the present study, AA7075 alloy under solution-treated and fully annealed conditions was subjected to integrated extrusion–Ecap at ambient temperature. It was demonstrated that under fully annealed conditions, deformation was homogeneous in both the microscopic and macroscopic aspects. Wide deformation bands were observed under solution-treated conditions, indicating the inhomogeneity of the microstructure due to the high strain-hardening rate of the material. The true stress-true strain data acquired from tensile testing of the extruded parts of samples was used for the finite element analysis of the subsequent Ecap stage. The results of finite-element method simulations showed large corner gap formation under solution-treated conditions, which is the main reason for development of macroscopic shear bands. The more uniform microstructure obtained in the full annealed condition was also attributed to the low work hardening rate during plastic deformation.