Electrode erosion in high power thermal arcs

Abstract

The present contribution is primarily focussed on electrode erosion phenomena. A model is described for predicting electrode wear. In our model of the cathode operation we follow the arguments of Ecker [“Electrode Components of the Arc Discharge”, Ergebnisse der exakten Naturwissenschaften, Vol. 23, 1961], considered to be the most successful model to date describing quantitive features. A comparison of various erosion mechanisms at tungsten cathode during operation in high power arcs shows that melting and evaporation of the cathode is the main erosion process. A model calculation renders that a local temperature of the arc root of about 4000K is nessecary for sufficient thermionic emission of electrons. © 1992 IUPAC