Atomic investigations on the mechanical properties of CoCrNi medium-entropy alloy nanowires

Abstract

This work investigated the mechanical properties of CoCrNi medium-entropy alloy (MEA) nanowires under uniaxial tensile loading along three crystallographic orientations [100], [110] and [111]. The face-centered cubic (FCC) single-crystal CoCrNi nanowires exhibit pronounced anisotropy Molecular dynamics simulations were employed to provide atomic-level insights into the plastic deformation mechanism. The surface effect causes dislocations to nucleate at the free surface and slip inward. The temperature effect was also considered. Under identical geometric configurations, crystal orientations, and temperatures, interatomic interactions govern key mechanical properties such as Young's modulus and yield strength. Simulation results reveal a strong linear correlation between the average atomic force and mechanical performance across eight representative FCC metallic nanowires (Al, Au, Ag, Cu, Ni, Al19Mg alloy, FeCoCrCuNi high-entropy alloy (HEA), and CoCrNi MEA). This study delivers novel insights into the mechanical behavior of metallic nanowires and offers guidance for the rational design of alloy nanowires.