The stress–strain response of nanocrystalline metals: A statistical analysis of atomistic simulations

Atomistic simulations of the tensile deformation of three-dimensional nanocrystalline Al samples at constant strain rate and temperature are analyzed in terms of grain-averaged shear produced by dislocation slip and the grain-averaged resolved shear stress during deformation. To assess the influence of the grain-boundary character on the deformation behavior, three samples with different microstructures but the same average grain size were simulated. Detailed analysis of the atomic processes allowed correlation of the stress signature of slip events with typical dislocation processes related to nucleation and propagation. The results of the mesoscopic analysis of the atomistic simulations are discussed in the framework of micromechanic models for nanocrystal plasticity.