Influence of graphite tool electrode shape on TWR and MRR at EDM

Abstract

Electrical Discharge Machining (EDM) is one of progressively developing machining technology. Its advantage over other progressive machining technologies is the high achieved accuracy of the machined surface. Moreover, in this case, it is machining without force, which means that the mechanical properties of the material to be machined do not impose almost any limits. However, during EDM, the material is not only removed from the workpiece, but also from the tool electrode, causing wear. However, a number of factors have an impact on the Tool Wear Rate (TWR) during the electrical discharge process. It is mainly its chemical and physical properties, the type of material being machined, but also its geometric shape. Therefore, based on the experimental measurements performed, the aim of the paper was to identify the influence of the geometric shape of the graphite tool electrode on the TWR and MRR size during EDM of tool steel EN 90MnCrV8. On the basis of the obtained results, set recommendations for the correct choice of the geometric shape of graphite tool electrodes used in EDM tool steels.