Influence of Interface Roughness on Cold Roll Bonding Characteristics of CU/Al/CU Laminated Sheet

Abstract

Influence of roughness of contact surface of C1020 copper and A1050 aluminum sheets on bonding characteristics was experimentally investigated in roll bonding of copper/aluminum/copper laminated sheet at room temperature. The contact surfaces of the sheets were roughened by emery paper and grindstone prior to roll bonding. Minimum reductions in thickness for bonding (higher than 0.9 in area fraction of bonding at the contact surface) were 63%, 55% and 50% in the laminated sheet with no surface treatment (mean arithmetic roughness Ra=0.1 μm), emery paper surface treatment (Ra=1.2–1.7 μm) and grindstone surface treatment (Ra=3.1–3.6 μm), respectively. On the other hand, the bonding strength of the laminated sheet with/without surface treatment was lower than 10 MPa. In roll bonding of the laminated sheet with large interface roughness, the elongation and relative sliding of the sheets at the contact interface of the sheets in rolling direction were reduced to approximately 90% and 35%, respectively. The bonding mechanism of the laminated sheet with large interface roughness was discussed from viewpoints of the deformation and the relative sliding in roll bonding.