(152453)Effects of asymmetry and annealing on interfacial microstructure and mechanical properties of Cu/Al laminated composite fabricated by asymmetrical roll bonding

摘要

Cu/Al laminated composite was fabricated by means of asymmetrical roll bonding and annealing process. The interfacial microstructure and mechanical properties of clad sheets were studied to explore the influence of rotation speed ratio and annealing temperature. The characteristic of interfacial bonding and distribution of intermetallic compounds were analyzed via the fracture behaviour of interface. The results reveal that asymmetry in roll bonding and subsequent annealing improve the interface with a three-layer structure. Due to thermal diffusion, large numbers of intermetallic compounds form in the interfacial interlayer, including Al_2Cu, AlCu and Al_4Cu_9 from aluminium to copper matrix. The increasing annealing temperature enhances the microhardness of interface and weakens the interfacial bonding. The clad sheet with rotation speed ratio 1.3 has higher bond strength and better tensile properties. High rotation speed ratio of rolls reduces the bond strength due to decreasing rolling force, though the breakage of metal surface is promoted. The interfacial interlayer fractures along the sublayer adjacent to copper matrix in peeling tests.