Polycrystal modeling of hot extrusion texture of AZ80 magnesium alloy
(State Key Laboratory of Mechanical System and Vibration, Department of Mechanical Engineering,
Shanghai Jiao Tong University, Shanghai 200240, China)
Shanghai Jiao Tong University, Shanghai 200240, China)
Abstract: The visco-plastic self-consistent (VPSC) model is extended to take the dynamical recrystallization (DRX) into account so that the hot extrusion texture of AZ80 magnesium alloy can be properly modeled. The effects of extrusion temperatures and imposed boundary conditions on the resulting textures were investigated, and good agreement can be found between the simulated and the measured extrusion textures. The simulated results show that the DRX grains are responsible for the formation of the fiber component since the poles of the DRX grains are tilted away from those of the unrecrystallized grains during the formation of their high angle boundaries (HABs). Furthermore, the basal poles of the grains are favorably oriented to the transversal direction (TD) where the imposed deformation is larger due to lower slip resistance of the basal slip. The elevated temperature enhances the activity of pyramidal ác+a？ slip modes and gives rise to a larger recrystallized volume fraction, resulting in a weakened extrusion texture.
Key words: AZ80 magnesium alloy; polycrystal plasticity; texture; hot forward extrusion; dynamic recrystallization