Effect of amorphous phase on the migration mechanism of basal/prismatic interface in Mg alloys

Abstract

A dual-phase nanostructured amorphous/crystalline model is an effective method to improve the mechanical properties of Mg alloys. However, the fundamental strengthening mechanism related to the interaction between basal/prismatic (BP) and amorphous phase in the dual-phase Mg alloys is still unclear. Here, the effects of the size and spacing of amorphous nanopillars on the mechanical properties and the BP interface migration behavior of the bicrystalline Mg alloys are investigated by the molecular dynamics simulation method. The results show that due to the attraction of amorphous nanopillar to interfacial dislocations, the introduction of amorphous nanopillar reduces the yield stress of the bicrystalline Mg alloys, and the yield stress decreases with the increase of the amorphous nanopillar radius. The results indicate that the amorphous nanopillar has an obvious blocking effect on the migration of the BP interface, and the larger the radius of amorphous nanopillars (or the smaller the spacing of amorphous nanopillars), the more obvious the strengthening effect. In addition, the migration mechanism of the BP interface in the bicrystalline Mg alloys is analyzed in detail.