Contact erosion of Ag/SnO/sub 2//In/sub 2/O/sub 3/ made by internal oxidation and powder metallurgy

Ag/SnO/sub 2//In/sub 2/O/sub 3/ electrical contacts are used to replace Ag/CdO and are typically manufactured by internal oxidation. Indium was added primarily to control internal oxidation microstructure. This study compares several electrical contact erosion properties of weld strength, switching life and arc eroded surface contact resistance of contacts made by internal oxidation and powder metallurgy. This is compared with some prior work of Ag/SnO with additives to determine if indium has specific performance advantages that justify the high cost of the indium.