Effect of AlCu constituent layer thickness discrepancy on the tensile mechanical behavior of Cu/AlCu/Al layered composites: a molecular dynamics simulation.

Nano-polycrystalline Cu/AlCu/Al layered composites with different layer thicknessesof single-crystal AlCu constituent are constructed. The effects ofon the strength and fracture modes of nano-polycrystalline Cu/AlCu/Al layered composites are systematically investigated by molecular dynamics simulations. The uniaxial tensile results show that the ultimate strength and fracture mode of the nano-polycrystalline Cu/AlCu/Al layered composites do not change monotonically with the change of single crystal AlCu constituent layer thickness, the ultimate strength peaking at= 2.44 nm, and the toughness reaching the optimum at= 4.88 nm. The improvement of deformation incompatibility between Cu, Al and AlCu components increases the ultimate strength of polycrystalline Cu/AlCu/Al laminated composites. Due to the high activity of Cu dislocation and the uniformity of strain distribution of single crystal AlCu, the fracture of nano-crystalline Cu/AlCu/Al layered composites changes from brittleness to toughness. This study is crucial to establish the organic connection between microstructure and macroscopic properties of Cu/Al layered composites. To provide theoretical basis and technical support for the application of Cu/Al layered composites in high-end fields, such as automotive and marine, aerospace and defense industries.