High Current Erosion of Ag/SnO2 Contacts and Evaluation of Indium Effects in Oxide Properties

The pressure to replace silver-cadmium oxide (Ag/CdO), which has been a preferred material for many contact applications, presents a continued need for data to allow for informed design decisions. In this study the comparison of performance between silver-tin oxideindium oxide (Ag/SnO2/In2O3) compositions and Ag/CdO and other Ag/SnO2 compositions made with other additives is expanded. This study compares high energy interruption, reignition, static gap, contact resistance and medium duty erosion results over compositions with similar oxide levels made by both internal oxidation and powder metallurgy. Changes in performance with variations in indium content are explored. This study extends the prior work done on these contact compositions which compared weld strength, switching life and arc eroded surface contact resistance of contacts.