Peeling: a failure mode of arcing contact

The materials or bonding interfaces of arcing contacts separate along a plane parallel to the contact surface. Different peeling modes are presented, and the possible mechanisms are discussed. The basic parameters affecting the formation of peeling are quite simple, namely, the arcing heat, and the strength (material strength and interface bonding strengths) of the contact assembly. Whereas the main source of heat is from arcing, it can be postulated that peeling will tend to occur in the phase which produces the most severe arcing. Generally speaking, it is the phase first to make and last to break. The severity of peeling depends on the switching device design as well as material integrity and bonding soundness. The progress of peeling can be slowed down if the device is so designed that arcing duration and contact bounce are kept minimum