Research on Dynamic Recrystallization Behavior of GWZK134 Alloy Based on Laasraoui-Jonas Dislocation Density Model

A uniaxial isothermal compression test was performed using Gleeble-3500D thermal simulation testing machine, and the dynamic recrystallization behavior of the GWZK134 alloy at deformation temperature of 360 ℃ to 480 ℃ and strain rate of 0.001 s^-1to 1 s^-1 was studied.Based on the hexagonal closepacked (HCP) structure of magnesium alloy, an improved model of Laasraoui-Jonas (L-J) dislocation density was established. The results show that the dynamic recrystallization volume fraction of GWZK134 alloy increases with increasing temperature and decreases with increasing strain rate.During the deformation process, the dynamic recrystallization occurs from nucleation at the grain boundaries, and gradually expands to the surrounding grains.As the temperature increases or the strain rate decreases, the flat grains caused by shear stress under compression conditions gradually become equiaxed. The comparison between numerical simulation and experimental data shows that the established model is more accurate in studying the dynamic recrystallization behavior of the alloy.