Joining of Copper and Aluminum Alloy A6061 Plates at Edges by High-Speed Sliding with Compression

Abstract

By using the joined or welded materials of dissimilar metals, the characteristics and performance of products and parts can be improved. The combination of copper and aluminum is difficult to weld. In this study, the impact joining of copper C1100 and aluminum alloy A6061-T6 plates at the edges was investigated to explore the appropriate joining conditions. The plates are joined with newly created surfaces generated by the high-speed compressive deformation with sliding motion. The shape near the interface was a tapered trapezoid with a flat top. The joining length in the plate thickness direction was shorter than the plate thickness, and notches were observed near both plate surfaces. The length became slightly longer by setting a larger top width of the C1100 plate than that of A6061-T6. The joint efficiency increased by approximately 10%. Applying the emery paper finish to the surface of the plate eliminated the non-joining result in multiple experiments. The finishing direction is effective only in the longitudinal direction of the plate. In the tensile test on the dumbbell-type specimen with reduced thickness to eliminate notches, most results showed a fracture at the C1100 portion. The estimated temperature rise of the C1100 is more than about 250 K during the impact deformation. Hence, the strength of the A6061-T6 becomes lower than that of C1100 during the process, and the softened layer of aluminum comes out under pressure, resulting in good joining performance.