Performance of Difference Electrode Materials in Electrical Discharge Machining of Tungsten Carbide

Abstract

Problem statement: Electrical Discharge Machining (EDM) is now a well-established machining option in many industries. Tungsten carbide (WC-Co) is an important tool and die material mainly because of its high hardness, strength, wear resistance and high melting point. Normally, EDM is capable of machining geometrically complex or hard material component, that are precise and difficult to machine. The objective of this research is to study the performance of different electrode materials on tungsten carbide workpiece with EDM process. Approach: The electrode materials were graphite (Poco EDM-3), copper-graphite (Poco EDM-C3) and copper-tungsten (solid).The important parameters were discharge current, on time, off time, open-circuit voltage and electrode polarity. A workpiece material was a tungsten carbide (W 90-Co10). Results: The results show that the electrode negative polarity performs very well, Poco EDM-3 gives higher Material Removal Rate (MRR). Both powder electrode (EDM-3 and EDM-C3) give the better MRR and EWR more than solid electrode. Conclusion: The suitable duty factor is 11%. The Surface Roughness (SR) of copper-tungsten give the best when current peak intensity not over 20 amperes.