Research on bonding mechanism of Cu/Al corrugated composite plates rolled by flat finish roll bonding

Abstract

Cu/Al composite plates with excellent properties were prepared using a new type of corrugated cold roll bonding (CCRB) + flat finish roll bonding (FFRB) process. In this paper, the bonding mechanism and interface strengthening mechanism of FFRB process were studied by experimental and numerical simulation methods. Furthermore, the mechanical properties of typical positions were studied. The results indicate that the FFRB process reduces the difference in bonding properties between the peak II and trough II. The bonding strength increases with the increase of reduction. When the reduction reaches 60%, the peel strength of interface at peak II and trough II is 45.04 N/mm and 35.83 N/mm, respectively. Meanwhile, the strong bond at the interface is conducive to transferring the center of strain localization (SL) to the Al side with excellent plasticity, delaying the necking and fracture of Cu/Al composite plates. After FFRB, Cu/Al composite plates develop from the annealed metallurgical bonding interface to the staggered distribution of metallurgical bonding and new bonding interface. The newly formed bonding interface and the particle pinning effect of the intermediate metal compounds (IMC) fragments work together to strengthen the bonding performance of the composite plates.