Accommodation of Intergrain Sliding through Grain Boundary Migration in Deformed Nanomaterials
A new micromechanism for accommodation of intergrain sliding in nanocrystalline metals and ceramics is suggested and theoretically described. The micromechanism represents the stress-driven migration of grain boundaries. In the framework of the suggested approach, intergrain sliding and stress-driven migration of grain boundaries accommodate each other, in which both these processes are intensified, and their combined action enhances ductility of a nanocrystalline material. We calculated the conditions at which intergrain sliding and stress-driven migration of grain boundaries cooperatively occur in nanoscopic grains in the athermal regime.