Inhibition effect on the evolution of a twist grain boundary for an Al/Ni bimetal interface under torsion

By using a molecular dynamics method with EAM potential, we study the evolution phenomena of metal twist grain boundaries (GBs) in the [100], [111] and [110] orientations, together with their bimetal interface, under anticlockwise and clockwise torsions. Our results show that there are different evolution behaviors of the GB screw dislocations for single metals (Al and Ni) and their bimetal interface (Al/Ni) under torsion. Specifically, for the single metals in the [100] and [111] orientations, their GBs evolve toward lower or higher angle twist GBs depending on the twist direction. For Ni in the [110] orientation, the dislocations spread not only in the GB region but also in the grain interior. However, for the bimetal interface, the propagation of dislocations is not only reduced dramatically but also limited to the interface region, showing that there is an inhibition effect. Therefore, such an inhibition effect can enhance the stability of nanomaterials which is very useful for the further design of nanodevices.