The Formation of Grain Boundaries during Plastic Deformation of LiF Single Crystals

The microstructural evolution of 100-plane-oriented LiF single crystals has been studied during plastic deformation at T = 1073 K. It has been shown that plastic deformation leads to formation of low-angle grain boundaries and their transformation to high-angle ones. Further plastic deformation leads to intensive grain boundary migration after some critical strain. The type of structural changes occurring in LiF single crystals is determined by the character of the crystallographic slip. The reasons for critical strain existence, and for the transition from 'rotation' dynamic recrystallization to one of 'migration', are discussed. (Author)