Size-Dependent Tensile Behavior and Dislocation Dynamics in Cu and Ag Nanowires: A Molecular Dynamics Study

Abstract: By using molecular dynamics simulations, the research examine how copper and silver nanowires respond to tensile loading in order to clarify their nanoscale deformation mechanisms. The results demonstrate that these two metal nanowires follow notably different stress - strain trends, with silver wires exhibiting greater elastic stiffness and higher yield points at equivalent diameters - an effect likely rooted in silver's stronger atomic bonding and more stable microstructure. A pronounced size effect is observed: as the wire diameter diminishes, both the yield strength and ultimate tensile strength increase substantially, a behavior driven by the higher proportion of surface atoms that enhance dislocation nucleation and mobility. Atomistic analyses further underscore the dominant role of dislocations during plastic deformation, and in particular reveal that surface - initiated dislocations in thinner wires critically affect their fracture behavior.