Grain boundary evolution in copper bicrystals was investigated during uniaxial tension at 10 K. Grain boundary structures were generated using molecular statics employing an embedded atom method potential, followed by molecular dynamics simulation at a constant 109/s strain rate. Interfacial free volume was continuously measured during boundary deformation, and its evolution was investigated both prior to and during grain boundary dislocation nucleation. Free volume provides valuable insight into atomic-scale processes associated with stress-induced grain boundary deformation. Different boundary structures were investigated in this work to analyze the role of interface structure, stress state and initial free volume on dislocation nucleation. The results indicate that the free volume influences interfacial deformation through modified atomic-scale processes, and grain boundaries containing particular free volume distributions showed a greater propensity for collective atomic migration during inelastic deformation.

Evolution of Structure and Free Volume in Symmetric Tilt Grain Boundaries during Dislocation Nucleation. G.J.Tucker, M.A.Tschopp, D.L.McDowell: Acta Materialia, 2010, 58[19], 6464-73