Cooperative toughening mechanism of nanocrystalline materials by grain rotation and shear-coupled migration of grain boundaries

摘要

A theoretical model is proposed to illustrate the cooperative effect of nano-grain rotation and shear-coupled migration of grain boundaries on toughening of nanocrystalline materials. The toughening mechanism is embodied by an effective stress intensity factor near the tip of a mode Ⅰ crack. The result shows a possibly effective toughening mechanism in nanocrystalline materials.