Molecular dynamics study of defect and dislocation behaviors during tensile deformation of copper-silver core-shell nanowires with varying core diameter and shell thickness

Abstract

Core-shell type nanostructures have drawn much attention among material researchers as they exhibit exceptional properties due to their unique structure. Among different core-shell nanostructures, copper-silver core-shell nanostructures are widely investigated in recent days for exhibiting different unique properties like very high mechanical strength. Molecular dynamics simulations were carried out to investigate the underlying deformation mechanism during tensile testing of copper-silver core-shell nanowires with varying core diameter and shell thickness. The Wigner-Seitz defect analysis was used to calculate the total number of point defects like vacancies and interstitials during the entire deformation process. The type, number, and total length of dislocation segments were thoroughly investigated throughout the different stages of deformation. The effects of varying core diameter and shell thickness on the defect and dislocation configurations were also studied. Thus, this study helps us to understand the underlying mechanisms or factors that contribute to the ultra-high strength and mechanical properties of Cu-Ag core-shell nanowires with varying core diameter and shell thickness.