Review of Mechanisms of Nanograin Generation

Аннотация

Abrief review of the theoretical models which describe specific plastic deformation mechanisms of nanograin generation in nanocrystalline and ultrafine-grained materials is presented. In the framework of the models, formation of new nanograins and nanograin chains occur through stress-driven splitting and migration of grain boundaries near crack tips and grain boundary structures containing disclination dipoles and quadrupoles. Stress-driven migration of mobile grain boundariesserves as a specific plastic deformation mode and resultsin formation of new nanograins and nanograin chains.