Molecular Dynamics Study of Influences of Non-Glide Stress on 〈a〉 Slips in Magnesium

Abstract

In order to investigate influences of non-glide stress on slips in magnesium (Mg), we carried out molecular dynamics (MD) simulations of shear deformations for slips with ⟨a⟩ Burgers vector under several normal stress conditions. In the present study, we adopted two kinds of interatomic potentials, embedded atom method (EAM) and modified embedded atom method (MEAM) potentials, which have different activities of deformation modes. For basal slip, extended dislocations were generated and then glided on the basal planes, irrespective of the applied normal stress conditions as well as the adopted interatomic potentials. On the other hand, in simulations for first-pyramidal slip, distinct gliding of a dislocation was not observed, and alternatively the shear deformation was mediated by [1101] twinning. The deformation behaviors observed in simulations for prismatic slip depended on the applied normal stress as well as the interatomic potential. These results imply that not only resolved shear stress for each deformation mode but also non-glide stress components affect the deformation behavior of Mg.