Micro-hole machining of copper using the electro-discharge machining process with a tungsten carbide electrode compared with a copper electrode

This paper describes micro-hole machining of a copper plate using the elect ro-discharge machining (EDM) process. Tungsten carbide was selected as the material for the electrode and compared with a copper-electrode. A precisio n centreless grinding process was employed to grind the electrode down to t he desired diameter A series of experiments were performed on a traditional EDM machine to investigate the effects of electrode material polarity sett ing and of a rotating electrode. Results have shown that electrode wear and hole enlargement are both smaller when positive polarity machining is sele cted; whereas electrode wear is larger and machining speed is higher when n egative polarity machining is selected. High-quality micro-hole machining i n copper can be achieved by the proposed method.