Influence of planar defects on the mechanical behaviors of spherical metallic nanoparticles

Abstract

In present study, we adopt molecular dynamics simulations to investigate the influ-ences of typical planar defects, including twin boundaries (TBs), stacking faults (SFs) and grain boundaries (GBs), on the mechanical properties of fcc copper nanoparticles. Groups of nanoparticle samples, including defect-free single crystal and those with specific de-fects, are examined for elastic modulus, yield strength, and deformation mechanisms. De-tailed results reveal that the elastic behavior of nanoparticles can be well described by a modified theoretical model regardless the type of defects. While the planar defects have negligible influence on the elastic modulus, they significantly enhance the yield strength of nanoparticles. Notably, nanoparticles containing fivefold TBs exhibit the highest yield stress, i.e. ~ 17.0 GPa, even surpassing that of the defect-free counterparts, i.e. ~ 10.0 GP. Analysis of atomic deformation unravels that the distinct yielding behaviors are attributed to the activation of different slip systems and the nucleation of dislocations at specific preferential sites. These findings highlight the potential of fabricating planar defects to tailor the mechanical properties of metallic nanoparticles for targeted applications in nano-technology and materials science.