Effect of Powder-Mixed Dielectrics on Performance Measures and Surface Morphology During PMEDM of Ti6Al4V

Electro-discharge Machining (EDM) advantages are limited by its limitations caused by the process instability. Powder Mixed EDM (PMEDM) is one of the processes which is used to maintain/improve the process stability by providing the space for effective removal of debris from the machining zone. The process improvement mainly depends on the thermophysical properties of the added powders. Therefore, in this work, an attempt is made to study the effect of addition of the conductive and semi-conductive powders with 1:1 proportion, i.e. 1 g/l Graphite (Gr) and 1 g/l Boron Carbide (B₄C) together in the dielectric fluid on EDM outputs such as Material Removal Rate (MRR), Surface Roughness (SR), Tool Wear Rate (TWR), and Percentage of Over Cut (OC). These responses are compared with the results obtained by adding 2 g/l powder to the dielectric fluid individually. It was observed that the addition of combination of powders results in moderate MRR, better SR, TWR, and percentage of OC compared to the addition of individual powders. In addition to this, the machined surface features and the possible elemental compositions of the machined surfaces were analysed using FESEM, EDS and XRD.