Contact Erosion Pattern of DC Break Arcs

Contour figures of crater structures and changes of erosion pattern were examined as a function of operations for break arcs on Au, Ag, Cu, and Ni contacts in a resistive circuit. Erosion pattern and crater structures estimated from the cathode spot behavior were confirmed, and the distinctive crater structures for each contact material were estimated by observing and analyzing closely the cathode spot behavior after a large number of operations. The size of eroded area for each contact corresponded to the values of the maximum moving width (lmw) of the cathode spot behavior for each contact material. A knowledge of the formation of the uniform erosion pattern was discussed from the present results.