Effects of Strain Rate and Initial Crack Position on Fracture Behavior and Mechanical Property of Cu/Zr Nanomultilayers
Abstract - Moleculardynamics (MD) simulations are used to investigate in detail the deformation behavior and mechanical properties of the Cu/Zr nanoscale metallic multilayer (NMM) during the tensile process. Considering the influence of factors such as strain rate and position crack, it is evaluated carefully in detail through a stress-strain graph, dynamic responses, dislocation evolution, and dislocation density of the Cu/Zr samples. The obtained results show stress increases with increasing strain rate, and the stress of specimen with boundary crack is smaller than that of cracks at Cu and Zr layers. The stacking fault appears densely in the Cu layers due to the phase transformation from FCC to HCP, while the amorphous structure is dominant in the phase transformation of the Zr layer. Shockley partial dislocations account for a large number of dislocations that form during deformation. Dislocation density is increased significantly with increasing strain rate, and crack location significantly affects dislocation density during deformation.
Keywords - Molecular dynamics; Tension; Strain rate; dislocation density; Position crack.