Optimization of changing polarity: in Powder Mixed Electric Discharge Machining (PM-EDM)

Electrical Discharge Machining (EDM) is a well-established non-conventional machining process for the machining of electrically conductive and difficult-to-machine materials. But its applications are limited because of the slow machining rate and poor surface finish. Powder mixed EDM (PMEDM) is unitary of the recent progresses in the EDM process in which powder particles mixed in the dielectric fluid results in higher machining rate and better surface quality.In straight polarity or normal polarity of EDM, workpiece is positive and tool is negative. When workpiece is negative and tool is positive, this type of polarity is commonly known as reversed polarity. As discussed earlier, energy dissipation into the anode is greater than cathode during sparking.