Molecular-dynamics computer simulations of a model Ni nanocrystalline sample with a mean grain size of 12 nm under uniaxial tension is reported. The microscopic view of grain-boundary sliding is addressed. Two atomic processes are distinguished in the interfaces during sliding: atomic shuffling and stress-assisted free-volume migration. The activated accommodation processes under high-stress and room-temperature conditions are grain-boundary and triple-junction migration, and dislocation activity.

• Received 8 March 2001

DOI:https://doi.org/10.1103/PhysRevB.64.224105