Effect of Different Bending Angles on the Microstructure and Texture Evolution of AZ31 Magnesium Alloy at High Temperature

To investigate the microstructure and texture evolution of AZ31 magnesium alloy under different bending angles at high temperature, OM and EBSD were used to systematically analyze the inner and outer microstructures under bending angles of 150°, 120°, and 90°. The results show that twinning on the inner side is more pronounced at high temperature. As the bending angle decreases, the number of DRX grains increases and their distribution becomes more uniform. Texture evolution exhibits asymmetry: inner orientations rotate toward RD and weaken with decreasing angle, while the outer side maintains a strong basal texture along ND, slightly weakening only under 90° large strain. Grain evolution progresses from the coexistence of SRX and early DRX, to extensive subgrain formation, and finally to full DRX development. The outer side stores more deformation energy through dislocation pile-up and subgrain formation, whereas the inner side more readily transforms LAGBs into HAGBs via DRX and twinning, leading to more pronounced local strain inhomogeneity and hardening on the outer side. The evolution of grain orientation keeps basal slip dominant; with decreasing bending angle, prismatic slip on the inner side becomes more favorable, while the favorability of pyramidal slip slightly decreases.