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 the use of nickel-plating of both aluminum and copper and copper-plating of aluminum ensures the greatest stability while bare aluminum in contact with tin- and silver-plated copper shows the poorest performance under different operating conditions.