| A special micromechanism for generation of nanoscale deformation twins the generation of nanotwin pairs at grain boundary (GB) dislocation pile-ups - in nanocrystalline and ultrafine-grained materials is suggested and theoretically described. In doing so, the generation of a pair of nanotwins at a grain boundary is realized through simultaneously occurring events of stress-driven splitting of a gliding GB dislocation into two partial lattice dislocations (emitted to adjacent grains) and a sessile GB dislocation. The energy and stress characteristics of the generation process in question are calculated. |
full paper (pdf, 416 Kb)