Effect of crystallographic orientation on deformation heterogeneity and mechanical properties of AZ31 alloy

The rolled (R sample) and extruded (E sample) AZ31 alloys show different texture characteristics, exhibiting a strong basal texture and a transverse direction-split texture, respectively. The increased crystallographic orientation heterogeneity in the E sample enhanced resistance to slip transfer, leading to a more pronounced slip accumulation at the grain boundaries between adjacent grains. This resulted in a higher hetero-deformation induced (HDI) stress in the E sample compared to the R sample. The enhanced yield strength observed in the E sample can be ascribed to the elevated Hall−Petch slope value, which was a consequence of the reduced geometrical compatibility factor. Meanwhile, more significant HDI strengthening and hardening effects synergistically improved both strength and ductility. Notably, high grain boundary misorientation angle contributed to the activation of non-basal slips, thereby alleviating local strain concentration near the grain boundary and improving the work hardening ability.