Deformation mechanisms in Al/Al2Cu/Cu multilayer under compressive loading

Abstract The promising mechanical, physical and chemical properties of Cu/Al layered composites are of high interest in extreme environments. It is therefore essential to understand the plastic deformation mechanisms and the variables affecting these properties. In this paper, LAMMPS code was used to calculate the lattice constants and elastic constants of Cu, Al, and Al2Cu structures, and the results were compared with experimental results to verify the accuracy of the BOP potential function. Also, the interface characteristics and the plastic deformation mechanisms under compressive loading in Al/Al2Cu/Cu multilayer with a coherent interface were numerically investigated. The interface model was established by MS software and subjected to molecular dynamics simulation to achieve the deformation mechanism at 300 K. The effects of temperature and strain rate on the compressive deformation of the system were investigated, and the results revealed the high sensitivity of the interface model to temperature. The increase in temperature reduced the interatomic forces, resulting in the decrease of the ultimate compressive strength of the material. Also, high temperature conditions promoted the nucleation of dislocations and produced high-density dislocations, which led to the decrease in material plasticity. The interface dislocation analysis revealed that the dislocation plasticity of the material presented strong strain rate dependence with increasing strain.