Influence of Diffusion Annealing and Subsequent Deformation on Bonding Strength of Cu/Al Bimetallic Strips

To implement the spirit of the State Council’s document on resolving the serious excess capacity contradiction, at the same time, to solve the problem of welding between copper and aluminum in the electricity, a bimetallic strip with Al–Cu–Al sandwich structure has been developed, of which copper accounts for nearly 80%. The solid phase rolling process was adopted for the strip. The interface and bonding strength of copper aluminum clad were studied by different diffusion annealing process and subsequent cold rolling deformation, and the conductivity of the laminated clad strip was tested. The results show that, the critical reduction rate to combine copper and aluminum together is 40%; the diffusion annealing temperature at 300 ℃ can be achieved with copper and aluminum metallurgy combination; the subsequent cold rolling deformation run up to 50%, which can increase the bonding strength of copper and aluminum clad strip; the conductivity of the copper/aluminum bimetallic strip are between the value of pure copper and pure aluminum. Welding adverse contradictions of copper and aluminum can be solved by cold rolling bonding at room temperature.