Enhanced mechanical properties of lamellar Cu/Al composites processed via high-temperature accumulative roll bonding

Cu/Al multilayers were produced by high-temperature accumulative roll bonding (ARB) methods up to three passes. To achieve a high bonding strength, prior to ARB processing, the Cu and Al sheets were heated to 350, 400, 450 and 500 degrees C, respectively. The mechanical properties were evaluated by tensile tests. The microstructure was examined by optical microscopy and scanning electron microscopy equipped with energy dispersive spectrometry. The ultimate tensile stress, the grain size and the thickness of diffusion layer of lamellar composites increase with rolling temperature. When the rolling temperature is 400 degrees C, the laminates show the highest ductility, but the yield stress is the lowest. As the rolling temperature further increases, both the yield stress and the ultimate tensile stress increase and the ductility decreases slightly. The mechanical properties of lamellar composites processed by low and high temperature ARB are determined by grain size and the thickness of diffusion layer, respectively.