Atomic simulation study on the effect of Y atom and grain boundary on tensile deformation in polycrystalline magnesium alloy
Wanwan Mei, Quanan Li, Xiaoya Chen
Abstract
The deformation of polycrystalline magnesium alloy was studied by molecular dynamics simulation. The influencing factors of tensile properties and its deformation mechanism were discussed. It was found that Y atom could inhibit the activation of basal <a> slip and promote the activation of pyramidal <c+a> slip. The crack was formed at the grain boundary with large orientation differences and propagated along the grain boundary. The stress concentration mainly occurred at grain boundaries, and its concentration decreases with the grain size decreasing. The formation of deformation twin was inhibited by small grains. The twin tended to nucleate at grain boundary and grew by absorbing dislocations. It was also found that new twin was preferentially formed near the old twin.