Evaluation of different platings for aluminum-to-copper connections

A number of coating materials commonly used for aluminum-to-copper connections were evaluated on the basis of their effect on the contact resistance force/torque relationships, the performance of coated joints under current cycling and fretting conditions, and ability to protect the contact against galvanic corrosion in saline and industrially polluted environments. The results showed that nickel plating of both aluminum and copper and copper plating of aluminum ensure the greatest stability, while bare aluminum in contact with tin- and silver-plated copper showed the poorest performance under different operating conditions.