A study was made of the atomic mechanism which was responsible for the emission of partial dislocations from grain boundaries in nanocrystalline metal. It was shown that, in a sample with a grain size of 12nm, grain boundaries containing grain-boundary dislocations could emit a partial dislocation, during deformation, by local atomic shuffling and stress-assisted free-volume migration. Nucleation occurred at a grain-boundary dislocation, which was removed upon nucleation and propagation. Free-volume migration occurred away from the nucleation region, before and after nucleation.

Atomistic Simulation of Dislocation Emission in Nanosized Grain Boundaries. P.M.Derlet, H.Van Swygenhoven, A.Hasnaoui: Philosophical Magazine, 2003, 83[31], 3569-75