Molecular dynamics simulations were used to study the tensile mechanical properties of face-centered cubic Ni nanocrystalline materials with a mean grain size of 12nm. Three samples were considered: as-prepared, annealed at 800K, additionally disordered in the grain boundary region. A reduction in plastic strain was observed as grain boundaries and triple-junction regions approached more equilibrium conditions. It was also observed that similar atomic activity within the grain boundary region occurred under both applied-stress and high-temperature conditions; thus indicating a close relationship between atomic-scale relaxation and inter-grain deformation mechanisms within the nanocrystalline system.

On Non-Equilibrium Grain Boundaries and their Effect on Thermal and Mechanical Behaviour - a Molecular Dynamics Computer Simulation. A.Hasnaoui, H.Van Swygenhoven, P.M.Derlet: Acta Materialia, 2002, 50[15], 3927-39