Achieving excellent strength-elongation synergy in corrugated Cu/Al laminated composites by flat finish roll bonding

Abstract

Despite years of efforts, it is unattainable to achieve ideal laminated metal composite materials as they generate limited plastic deformation. In this study, leveraging on a cold flat rolling process, a high interface bonding quality along with simultaneously enhanced strength-elongation synergy were achieved in the corrugated Cu/Al laminated composites. The microstructures and associated mechanical properties of the corrugated Cu/Al laminated composites at Peak and Trough zones were studied after flat finish roll bonding (FFRB) with 50 ∼ 60% reductions. The results indicate that the interface bonding property was significantly strengthened by the new firmly bonded interface zones and the fragmented intermetallic compound layers after FFRB. Especially, at 60% reduction, the shear strengths at Peak and Trough zones reach 126.36 MPa and 105.27 MPa, respectively, which are 514.59% and 49.71% higher than that of the original corrugated Cu/Al laminated composites. With increasing the reductions, the tensile strength of the flattened Cu/Al laminated composites has been improved significantly attributed to the fine-grain strengthening, dislocation strengthening, and hetero-deformation induced stress strengthening. It is worth noting that the interfacial strengthening, texture weakening and transition have occurred simultaneously at the Peak zone, which is responsible for the improvement in both strength and elongation.