Behavior of conical peaks under the action of the electrical discharges

Abstract

During the electrical discharge machining process, the electrical discharges are developing between the close asperities that exist on the tool electrode and workpiece surfaces, along a trajectory of minimum electrical resistance. As a consequence of the electrical discharges, small quantities of the electrode’s materials are melted or even vaporized and afterward removed from the machining gap. Various factors exert influence on the material removal from the peaks of asperities placed on the electrode’s surfaces. An experimental method of the simulation of the material removing process was designed and applied. Single electrical discharges characterized by distinct energies were generated between the conical peaks of the previously prepared test pieces made of some electroconductive materials and the flat surface of the copper electrodes. The quantities of the material removed from the conical peaks of the test piece materials under the action of electrical discharges were measured and used to determine empirical mathematical models. These models highlight the influence exerted by some factors specific to the electrical discharges (cone angle, the voltage between electrodes, the capacitance of the capacitors included in the discharge electric circuit) on the material removal from the conical peaks of the test pieces.