Interfacial bonding mechanism of Cu/Al composite plate produced by corrugated cold roll bonding

Corrugated cold roll bonding (CCRB) produces metal composite plate with improved mechanical properties compared with conventional methods, but the interfacial mechanism is not fully understood. Here, Cu/Al composite plate with good plate shape was produced by CCRB, and the bonding mechanism and strength along the corrugated interface were studied by experiments and finite element simulations. The results showed that the average bonding strength of Cu/Al composite plate produced by CCRB was nearly twice that of conventional composite plate at an average reduction of 40% during rolling. Strong friction shear stresses occurred at the interface of the corrugated composite plate, which promoted the plastic deformation of the metals and accelerated the rupture of the brittle interfacial layer. Electron backscattered diffraction analysis showed that higher degrees of grain elongation and refinement occurred in the matrices at the front waist and trough due to the stronger normal and shear stresses. Energy-dispersive spectroscopy line scans showed that the thickest atomic diffusion layer occurred at the front waist. The present combination of experimental and computational analyses provides insights into the underlying mechanism of mechanically improved metal composites prepared by CCRB.