A correlation of silver tin indium oxide-copper composite rivet interface bond quality and switching endurance life in DC relays

This work investigates contact life as a function of the contact internal interface bond quality. The comparison is made using resistive load under different DC power voltages and currents for different designs of composite rivets with different bond and silver metal oxide (AgMO) thickness. It demonstrates that the rivet bond is a predominant factor to contact life for higher switching power levels and less at lower powerlevels. A mechanism for contact interface bond deterioration is discussed in terms of contact surface melting, bond interface temperature, arc energy and AgMO layer thickness.