Grain boundary influence on the mechanical response to tensile loading for nanosized Cu beams modelled by MD simulations

摘要

The influence of grain boundaries on the mechanical properties of poly-crystalline metals is well known. Here we investigate the influence from a centrally placed grain boundary in nano-sized beams of Cu subjected to tensile loading. The crystallographic orientations in the grains are [100], [110] and [111]. The investigation is performed by means of molecular dynamic simulations employing the molecular dynamics free-ware LAMMPS. The Influence of the grain boundary was found to be substantial as compared to equally sized single grain beams. The grain boundary forced earlier plastic initiation and earlier ruptures in all cases. Further, one of the grains showed to be preferred as regards dislocation generation and slip. Also a clear correlation between dislocation density and variations in the axial stress - axial strain curve was found.