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 suc h degraded tin-lead connectors to service. This possibility has been explor ed with bench apparatus using plated tin-lead and plated gold to tin-lead c ontacts mated in a crossed rod configuration, The crossed rods were fretted until the contact resistance severely degrade d. Then the crossed rods were separated and various treatments were applied to the fretted surfaces. Included were a commercial contact cleaner and se veral different lubricants, After carefully returning the rods to their ori ginal 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 d egraded 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 connecto r systems to service.