Machining of SiC by ECDM process using different electrode configurations under the effect of pulsed DC

Electrochemical discharge machining is a process which combines the characteristic of electro-chemical machining and electric-discharge machining and has potential to machine electrically non-conductive materials such as glass, quartz, granite, etc. However, due to inherent associated problems with the process, its efficiency is low which gets further reduced with time especially while machining high strength high temperature resistant ceramics. To overcome this problem, pulsed DC power supply has been incorporated in the present study with three influential process parameters, i.e., applied voltage, duty factor and electrolyte conductivity to find their effect on volume of material removed from SiC with different electrode configurations. Results obtained indicate that volume of material removed from the workpiece increases with increase in supply voltage, duty factor and electrolyte conductivity. Pulsating nature of power supply has improved the machining performance and has reduced the tendency of cracking at high supply voltage while the use of abrasive electrode has partially relaxed the inherent limitations of the machining process. In this study, orbital motion of abrasive electrode has shown the maximum volume of material removed while rotary abrasive electrode has shown the increased volume of material removed compared to non-rotating brass electrode.