Atomistic simulations of mechanical deformation of high-angle and low-angle nanocrystalline copper at room temperature

Molecular dynamics simulations were performed to study the mechanical behavior of high-angle and low-angle nanocrystalline copper with the average grain size in the range of 3.7–6.7 nm at room temperature. Atomic configuration analysis indicates that the grain boundary sliding is the main deformation mechanism in the high-angle samples while both dislocation motion and grain boundary activities play an important role in the plastic deformation for low-angle (textured) samples. The grain boundary activities in the low-angle samples are manifested by migration, breakup and dislocation activities within grain boundaries themselves. It was found that the orientation of the grains to the tensile direction strongly affects the mechanical behavior of the textured samples.