Effects of {10-12} Twin Boundary on Nanotribological Behavior of Pure Mg: A Molecular Dynamics Simulation

Abstract

Twinning is a key plastic-deformation mechanism in magnesium (Mg) and Mg alloys. However, the effect of {10-12} twin boundaries on their nanotribological behavior remains unexplored in molecular dynamics (MD) simulations. In this study, single-crystal Mg model and double-crystal Mg model featuring a {10-12} twin boundary were generated. The effects of the {10-12} twin boundary on the friction behavior, dislocations, and von Mises strain-stress during friction and wear processes were investigated using MD simulations. The results indicate that the frictional force and coefficient of friction (COF) in the double-crystal Mg model containing a twin boundary were lower compared to the single-crystal Mg model under identical normal loads. Furthermore, interactions between periodic interfacial dislocations and other dislocations types significantly increased the dislocation density, reducing the von Mises shear strain and consequently improving the wear resistance of the double-crystal Mg model with a {10-12} twin boundary.