Characterization method for electric arc erosion based on the in-situ measurement of electrode surface morphology

Abstract

The electrical arc significantly influences the surface morphology and the performance of electrode. There has been ever increasing demand for the characterization method of arc erosion. In this work, an in-situ test rig has been described that makes it possible to measure the surface height point cloud data and the microscopic images consecutively during arc erosion cycling. Novel processing algorithms considering the eroded electrode morphology are proposed for characteristic parameters calculation including arc erosion volume, electrode gap and contact area. It has been observed that the inner layer metals of electrode are heated and ejected to the surface after arcing, which form higher bulges with pores. And the electrode gap decreases under higher arc erosion volume. Moreover, in the electrical endurance experiment, the change trends of contact area correlate well with the measured resistance. Based on the collected sensitive parameters, the cumulative arc erosion on the electrode surface is characterized.