Observation of Changes of Contact Surface Profiles of Ag and AgSnO2 Contacts during Switching Operations with an Optical Cross-Section Method

Ag and AgSnO₂ contacts were operated to break a DC inductive 14V-2A load current for 50,000 operations. During the switching operations, changes of a surface profile of the movable cathode electrode (more specifically, a crater growth process) were observed with the optical cross-section method at every 2000 operations. In addition, a surface of the mating stationary anode electrode (more specifically, a pip growth process) was also observed with an additional digital camera system. Certain differences in the crater and pip growth processes were observed with different contact materials.