Effect of Ni Foil Interlayer on the Interface Structure and Mechanical Properties of Hot-Rolled Al/Mg Composite Plates

In this paper, 5083 Al/AZ31B Mg composite plates with added Ni foil were prepared by hot rolling, and the effects of Ni foil thickness (0, 5, 10, 25, and 50 μm) on the interface microstructure and the mechanical properties of the Al/Mg composite plates were investigated. The results show that the Ni foil added at the interface is fractured due to inhomogeneous deformation, showing a discontinuous band-like distribution at the interface. The presence of the Ni foil hinders the single interdiffusion between Al and Mg. Instead, a mixed interface composed of Al, Mg, and Ni forms, which is conducive to improving the interfacial bonding strength. Furthermore, the addition of the Ni foil interlayer contributes to the dynamic recrystallization of Al and Mg substrates near the interface, refining the grains at the interface, changing the grain orientation on the Al side and having a certain strengthening effect. As the thickness of the implanted Ni foil increases, the bonding strength and the tensile strength of the composite plate first increase and then decrease, and the largest values were obtained when the thickness is 25 μm, which are 5.9 N/mm and 245.25 MPa.