The failure mechanisms of symmetrical tilt boundaries were investigated by using an atomistic technique. The fracture process was supposed to advance in steps that were related to the structural unit of the symmetrical tilt grain boundary. Such boundaries were shown to fail via a combined mechanism which involved dislocation emission in certain regions of the structural unit, followed by micro-cleavage, and again by dislocation emission. The overall toughness of the boundaries reflected the combined effect of the 2 processes.

Fracture Mechanisms of Symmetrical Tilt Grain Boundaries. D.Farkas: Philosophical Magazine Letters, 2000, 80[4], 229-37