The contact resistance and wear behaviour of separable electrical contact materials

• Published in: Wear 1989-05, Vol.131 (1), p.177-191
• Main Authors: Goodman, Simon J.N., Page, Trevor F.
• Format: Article
• Language: English
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/0043-1648(89)90253-6

The wear behaviour of two Au-Co electrodeposits has been examined using a reciprocatory sliding pin-on-flat geometry. The materials are typical of those used in high reliability electrical connectors, and loads (about 1–2.5 N) and conditions (ambient atmosphere) were chosen consistent with this application. Both electrical resistance and friction forces have been recorded as a function of sliding cycles and the resultant wear scars examined by scanning electron microscopy. Transmission electron microscopy has been used to determine the initial microstructure of the materials. Load-variant indentation hardness testing and static contact resistance measurements have also been employed to characterize the mechanical and electrical behaviour of the coatings prior to wear. It is shown that dynamic friction behaviour is consistent with the presence of a lubricating surface film though none is detectable by the static electrical method. Wear mechanisms for the gold coating materials are described and involve combinations of adhesion and ploughing. There appears to be significant microstructural control of the wear mechanisms.