Selection of Dielectric Media (Kerosene and Used Transformer Oil) towards Improving Efficiency of Powder-Mixed EDM

Abstract

In this work, application potential of copper powder added kerosene dielectric media has been compared whilst using suspended copper powder added with used transformer oil during electro-discharge machining of Inconel 718. Improvement in machining performance of Inconel 718 has been studied in purview of machining rate, EDMed surface morphology as well as topography. The following topographical measures viz. roughness average, intensity of surface cracks, thickness of the white layer developed onto the machined surface have been analysed. EDS and XRD analysis have been carried out to understand the extent of material migration, formation of intermetallic phases, grain refinement taking place during the machining process. The comparative experimental study has finally concluded that copper powder mixed used transformer oil has been the better choice between aforesaid two alternative PMEDM routes in view of machining performance of Inconel 718.