Make erosion mechanism of Ag/CdO and Ag/SnO2 contacts

The reason for the different make erosion behavior of contactor contacts made from Ag/CdO and Ag/SnO/sub 2/ has been investigated, separating the effects of the thermal stress due to the bounce arc from the mechanical stress due to contact closure. It appears that neither arcing without mechanical stress nor no-load switching without arcing is able to produce serious mass losses. Only the combined action of bounce arcs followed by mechanical impacts causes severe erosion phenomena, which are more pronounced in Ag/SnO/sub 2/ contacts, losing more obviously weakly adhering matter due to mechanical effects.<>