Crystal plasticity based modeling of grain boundary sliding in magnesium alloy AZ31B sheet

The aim of present work is to develop a crystal plasticity modeling approach to integrate slip, dynamic recrystallization (DRX) and grain boundary sliding (GBS) for simulating the deformation behavior and texture evolution of magnesium alloys at high temperatures. Firstly, the deformation mechanisms of an AZ31B Mg alloy sheet at 300 degrees C were investigated by examining texture and microstructure evolution during uniaxial tension and compression tests. DRX refines microstructure at strains less than 0.2, and subsequently GBS plays a significant role during deformation process. A GBS model is developed to evaluate strain and grain rotation induced by GBS, and implemented into the polycrystal plasticity framework VPSC. The VPSC-DRX-GBS model can well reproduce the stress-strain curves, grain size, texture evolution and significant texture differences in tension and compression tests due to GBS. The calculated GBS contribution ratio in tension is obviously higher than that in compression due to easier cavity nucleation at grain boundaries under tension loading.