Exploring the basal/prismatic slip transfer at grain boundaries in magnesium: A molecular dynamic simulation

Abstract

This study utilized the molecular dynamics method to investigate the slip transfer behaviors of edge and screw dislocations in magnesium at basal/prismatic grain boundaries (BPGBs), where the Burgers vectors and the slip planes are parallel across the GBs. The results demonstrate that when shear stress increases, the initially introduced basal dislocation migrates toward, interacts with a BPGB, and is transmuted to a prismatic dislocation and vice versa. The critical resolved shear stress for the basal screw dislocation transmutation is considerably higher than edge dislocation. The slip transfer from basal to prismatic slip has a higher resistance than the slip transfer from prismatic to basal slip. The influence of normal strain perpendicular to the slip plane and temperature was also analyzed to better understand the process of the interactions. Moreover, as the tensile strain increases, the basal to prismatic slip transfer is more easily facilitated.