Electro-erosion of metal surfaces

Abstract

Craters produced by single electrical discharges in kerosene under conditions similar to Electro-Discharge Machining were formed on the following metals: Al, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Ta, Ti, V, W, and Zn. Anode and cathode crater volumes were measured by a profilometer imaging technique and except for Nb, Mo and Ta, the cathode craters were always found to be larger. An empirical equation was developed to relate the volume of the electro-erosion craters formed to the physical properties of the electrodes. Crater morphology and surface texture were studied using both Scanning and Transmission Electron Microscopy. An Electron Microprobe was used to determine the distribution of cross deposited metal in the case of dissimilar electrodes. Crater volumes and morphologies resulting from single electrical discharges in liquid and dry nitrogen were shown to be radically different from those produced in kerosene.