Molecular dynamics study of plastic deformation of nanocrystalline palladium

Atomistic simulations of tensile and compressive deformation of threedimensional nanocrystalline palladium at room temperature and different strain rates were perfomed. Detailed analysis of tensile straining has revealed almost no plasticity and an absence of dislocation activity in the grains right up to the moment of intergranular cracking. During compressive straining the sample exhibits a plastic regime brought about by the motion of extended partial dislocations emitted from the grain boundaries. At higher compressive strains the deformation mechanism changes to one that involves full dislocations and twinning