The Best Arc Heater Regime for Minimum Copper Cathode Erosion

On the basis of the experimental investigations and simple theoretical model, which regards electrode erosion as ablation of the electrode material under the action of intensive heat fluxes in the arc spot, we give estimations of the range of operating regimes of copper cathode with the minimum erosion. We show, that application of a magnetic field for displacing of arc over the electrodes surface has a number of specific limitations from point of view of electrode erosion. These limitations are related with a variation in the energy parameters of the arc spot and heat transfer between electric arc and the electrodes under the variation of magnetic field. As a result, an optimal magnetic field exists, which is a function of an electrode temperature θ0 and derivative dθ/ds. Here θ0=T/Tf; Tf - melting point of electrode material; s = v/I0.5; v - arc velocity; I - current. We give here relationships and diagrams, which make it possible to evaluate the range of the operation of copper cathode with the minimum erosion