Effect of Solute Atoms on the Twinning Deformation in Magnesium Alloys

Abstract

Deformation twinning is an important plastic deformation mode in magnesium and magnesium alloys . In this work, the solid solution hardening effect on the twinning deformation in Mg–Al binary alloys was investigated using molecular dynamics (MD) simulations. In the MD modeling, we studied the effect of solute atom concentration on the nucleation stress and Peierls stress of twinning dislocations on the $\{ 10\bar{1} 2\}$ extension twin boundary (TB). The simulation results show that the nucleation stress of twinning dislocations decreases as the concentration of solute atoms increases, indicating a solid solution softening effect. However, the Peierls stress increases with the increasing concentration of solute atoms, suggesting a hardening effect. So, the total effect of solute atoms on the twinning deformation depends on the competition between these two effects.