An experimental study on surface erosion characteristics of contacts operated in nitrogen atmosphere

摘要

Ag, Pd and Cu contacts were operated in nitrogen atmosphere and in air to consecutively break a DC inductive load current up to 3 A, and the resultant contact surface erosion/transfer configurations were numerically evaluated with a digital scanning laser microscope. Specifically, in this study, diameter and height or depth of pips/craters formed on the contact surfaces were measured. As a result, interesting differences depending on surrounding atmosphere, load current values and contact materials were found. For example, in the case of Ag contacts with a load current of 3A, a deeper crater was likely to be formed on a cathode surface operated in nitrogen atmosphere than that operated in air. Some experimental data are presented herein.