Optimization of the laminated structure and mechanical properties of Cu/Ti composites via hard plate accumulative roll bonding

Abstract

A major challenge in traditional accumulative roll bonding of Cu/Ti laminated composites is the formation of shear bands and fracture of the Ti layer, which disrupt layer continuity and deteriorate the mechanical properties. In this study, Cu/Ti laminated composites were fabricated using hard plate accumulative roll bonding (HP-ARB). The evolution of the laminated structure, microstructure, texture, and mechanical properties was systematically investigated after HP-ARB0–3 cycles. The results showed that HP-ARB significantly improved the deformation coordination between the constituent layers, inhibited shear band formation and Ti layer rupture, and still maintained layer continuity after the 3rd HP-ARB cycle. With increasing HP-ARB cycles, the number of Cu/Ti heterogeneous interfaces increased significantly, accompanied by continuous grain refinement. The Cu and Ti layers predominantly underwent partial dynamic recrystallization and dynamic recovery, respectively. Meanwhile, the Cu texture evolved from a strong Brass texture to a strong S texture and finally to a nearly random texture, while the Ti texture gradually transformed from a strong basal and prismatic textures to a random texture with low anisotropy. Under the combined effects of grain refinement, work hardening and heterogeneous deformation induced (HDI) strengthening, the composites achieved high strength (518.5 MPa) and high elongation (18.7%). Among them, the HDI effect was reinforced with the increasing heterogeneous interfaces. These findings can provide theoretical and experimental support for the microstructure design of high-performance laminated composites.