Deformation Uniformity Optimization Design based on Multi-scale Simulation of AZ31 Magnesium Alloy ECAP

ECAP has obvious deformation heterogeneity, which results in residual stress in the deformed material and the stress affects the performance of the material. Therefore, the ECAP forming process of AZ31 magnesium alloy was simulated with multi-scale technique. Influence on extrusion deformation uniformity of the die corner, billet temperature, extrusion speed was studied. The analysis results show that die angle 100 °, billet temperature 260 ℃ and extrusion speed 1mm / s are the optimum process parameters and the deformation uniformity coefficient is only 3.782844. Microstructure simulation based on the CA program was conducted, and the result shows that the grain is refinement largely and the grain size of shear deformation zone of the inner corner and out corner is close, and the deformation uniformity is improved. This verifies that the optimal scheme is feasibly.