Macro–Micro–Nonuniform Deformation Behavior of 7B52 Laminated Aluminum Alloy under High-Speed Impact

Due to its low density, high tensile strength and excellent energy absorption capability, 7B52 laminated (7A52/7A01/7A62 layers) aluminum alloy is a promising material for the application of armored vehicles and tanks. With the rapid development of anti-armor weapons, there is an increasing need for 7B52 laminates with excellent impact resistance. However, the impact failure behaviors and related mechanisms of this laminated alloy remain unclear. In this work, the macro–micro–nonuniform deformation behaviors of a 7B52 laminated aluminum alloy after high-speed impacts (from 2700 to 5000 s−1) were investigated. The results revealed that the plastic deformation was mainly concentrated in the 7A01 and 7A52 layers of the 7B52 laminated aluminum alloy under high-speed impact, indicating nonuniform deformation of this alloy. The ductile 7A01 layer led to the blunting and deflection of cracks formed in the interlaminar 7A62 and 7A01 layers and thus prevented cracks from propagating into the 7A52 layer. Meanwhile, the nonuniform deformation between the 7A52 and 7A62 layers could be justified from adiabatic shear bands and precipitates. Deformation shear bands, transformation shear bands and then both were successively observed in the 7A52 layer, while only slight deformation was present in the 7A62 layer due to a much larger amount of η` precipitates effectively hindering dislocation movement. Therefore, nonuniform deformation was observed in the 7B52 alloy under high-speed impact.