Effect of layered structure on the impact performance and damage mechanisms of hot-rolled aluminum laminated composites

The layered structure significantly influences the impact resistance of dissimilar metal composites. Aluminum laminated composites (ALCs) with different stacking configurations—7A52/7A01/7A62 (S-H) and 7A62/7A01/7A52 (H-S)—were fabricated by hot roll bonding. The effects of the stacking configurations on the bending properties, impact toughness, ballistic performance, and failure mechanisms of these ALCs were investigated comprehensively. The results indicate that the laminated composites exhibited superior bending performances compared with monolithic aluminum plates. Regarding impact performance, the impact energy absorption of the H-S specimens reached 44.5 J, representing a 25% improvement over the S-H specimens and demonstrating superior impact toughness. In ballistic tests, the H-S specimen failed through a mixed mode of shear plugging and plastic deformation, whereas the S-H specimen experienced penetration and spallation failure. Compared with the monolithic 7A52, the 7A62 plates, and the S-H configuration, the ballistic limit velocity of the H-S structured laminate increased by 42.9%, 33.3%, and 14.9%, respectively. The high-strength layer 7A62 of the H-S specimen experienced intergranular fracture, leading to layer cracking and delamination. The ductile 7A52 backplate underwent substantial plastic deformation, which played a critical role in enhancing the ballistic resistance. The bonding interlayer 7A01 exhibited severe bending after impact without interfacial delamination, maintaining coordinated deformation and structural integrity among the components. • The ballistic limit velocity of the 7A62/7A01/7A52(H–S) structured ALCs is high than the 7A52, 7A62 plates, and 7A52/7A01/7A62(S-H) structured ALCs. • The H-S structured ALCs failed through a mixed mode of shear plugging and plastic deformation, whereas the S-H ALCs experienced penetration and spallation failure. • The ductile 7A52 backplate underwent substantial plastic deformation, which played a critical role in enhancing the ballistic resistance. • The bonding interlayer 7A01 exhibited severe bending after impact without interfacial delamination.