Motion of Magnetically Driven Arcs on Oxidized Electrodes

Experiments were carried out on a number of oxidized metals such as copper, brass, aluminum, and steel. Two kinds of rectangular electrodes were investigated, narrow and wide electrodes. On the narrow oxidized electrodes the arc moved slowly and sometimes discontinuously during its first run. During subsequent runs the arcs moved continuously along the same path of the first run with speeds which were ten times faster than the first run. On the wide oxidized electrodes however no slowdown of the arc was observed during its first run. It ran right away continuously with speeds similar to the subsequent runs.