Influence of mechanical design parameters on electrical contact performance

Long-time service data as well as data from current cycle testing on electrical contact resistance have been analyzed with respect to mechanical design parameters. The importance of the pressure distribution over the contact surface was studied for a constant surface force. The mechanical stresses acting over the contact surface have been calculated by the finite-element method for the type of contact investigated. It is found that a high specific contact pressure promotes lower contact resistance and favors their long-time stability. The pressure distribution on the contact surface has a significant influence on the aging properties of the connectors studied. It was confirmed that the aging behavior is strongly affected by the preparation methods. The aging mechanisms detected on the contact surfaces studied are fretting and formation of intermetallic phases. >