Fracture in LiF Bicrystals at Plastic Deformation

Abstract

Peculiarities of plastic deformation and crack initiation within a tilt boundary being “attacked” by screw or edge dislocations in isoaxial LiF bicrystals with various misorientation angles α = = 2 to 15° are studied by the single slip method. Cracks proved to appear within the boundary at a shear strain inversely proportional to the angle a in the first case, and not depending on a in the second case. Based on dislocation structure of deformed specimens, pattern and shape of cracks the conclusion is drawn, that crack formation occurs due to accumulation of grain boundary dislocations in the boundary, or due to opposite pile-ups arising at the boundary as a result of plastic deformation. [Russian Text Ignored].