Make erosion mechanism of Ag/CdO and Ag/SnO/sub 2/ contacts

The reason for the different make-erosion behavior of contactor contacts made from Ag/CdO and Ag/SnO/sub 2/, respectively, has been investigated at 400 A, separating the combined effects of the thermal stress due to the bounce arc and of the mechanical stress due to contact closure. It appeared that neither arcing without mechanical stress nor no-load switching without arcing are able to produce serious mass losses. Only the combined action of bounce arcs followed by mechanical impacts cause severe erosion phenomena, which is more pronounced in Ag/SnO/sub 2/ contacts, losing more obviously weakly adhering matter due to mechanical effects.<
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