Molecular dynamics simulation on spallation of [111] Cu/Ni nano-multilayers: Voids evolution under different shock pulse duration

Abstract Spalling behavior of multilayered materials has a tight correlation with shockwave loading conditions and heterointerfaces. Here, the dynamic response and spallation of [111] Cu/Ni nano-multilayered system under different shock pulse duration are investigated by molecular dynamics. Our work suggests that spallation occurs only in the Cu region instead of in Ni. Also, spalling mechanism transit from homogenous nucleation of voids within Cu layers to nucleation at Cu/Ni interfaces with growing shock duration, resulting in the drop of global spall strength. The recompaction result from the compressive wave is observed to blocks the cavitation’s aggregation, which proves the possibility of damage controlling by interface and impedance design at the atomic scale. Additionally, dislocation analysis shows a similar evolving process of dislocations in Cu and Ni. Longer shock duration is found to result in lower peak density of stair-rods.