Recovery of severely degraded tin-lead plated connector contacts due to fretting corrosion

The susceptibility of connectors with tin-lead plated contacts to fretting corrosion is well known. It would be advantageous to be able to recover such degraded tin-lead connectors to service. This possibility has been explored with bench apparatus using plated tin-lead and plated gold to tin-lead contacts mated in a crossed rod configuration. The crossed rods were fretted until the contact resistance severely degraded. Then the crossed rods were separated and various treatments were applied to the fretted surfaces. Included were a commercial contact cleaner and several different lubricants. After carefully returning the rods to their original position, several long movements were made to simulate the mating and unmating of a connector, and fretting was resumed. Preliminary results show that a contact cleaner may temporarily recover a degraded contact, but a lubricant is more effective. Although the avoidance of fretting degradation by optimal choice of materials and design is best, this work demonstrates that it may be possible to restore tin-lead connector systems to service.