Softening of nanocrystalline nanoporous platinum: A molecular dynamics simulation

Abstract Spinodal decomposition and voronoi tessellation are combined for the generation of nanocrystalline nanoporous model with grain size corresponding to ligament diameter and randomly distributed crystal orientations. A series of large-scale molecular dynamics (MD) simulations were performed and utilized to research on the mechanical behaviors of nanocrystalline nanoporous platinum (nc-NPPt) undergoing uniaxial tension. The relation between relative density and mechanical properties, together with related atomistic deforming mechanisms of as-generated nc-NPPt were analyzed. It is found that the existence of nanocrystals and substantial surface may lead to decreased tensile strength and increased plasticity of nc-NPPt, and the plastic deformation scheme of nc-NPPt is dominated by grain boundary movements. The present results will provide atomistic insights for understanding deformation mechanisms of nanocrystalline nanoporous metals as well as future mechanical optimization of nanoporous metals.