Effect of post-rolling annealing treatment and thickness of nickel coating on the bond strength of Al–Cu strips in cold roll bonding process

In this study, the effect of coating nickel and also its different thicknesses on the bond strength of Al–Ni–Cu layers was investigated. Furthermore, the effect of reduction in thickness and post-rolling annealing on the bond strength was evaluated in order to achieve the optimum parameter in rolling Al/Cu/Ni composites. So, after preparing samples, using peeling test, we investigated the bond strength of Al–Cu strips. The results showed that coating copper with nickel reduces the bond strength of Al–Cu strips. However, by increasing the thickness of coating, the bond strength was increased, reaching the highest level compared with the strips without coating. Also, the increase in the reduction enhanced the bond strength of the layered strips. Yet, a decrease in bond strength was achieved by post-rolling annealing of the layered strips.

► The threshold reduction was increased by coating of nickel on Cu strips.
► Low thickness of Ni coating on Cu reduced the bond strength of Al–Cu strips.
► Increasing the thickness of coating enhanced bond strength of Al–Cu strips.
► Annealing treatment of Al–Ni–Cu composite formed intermetallic compounds.
► Bond strength was decreased by post-rolling annealing treatment of Al–Ni–Cu.