Experimental Investigation on EDM of Inconel 718 Alloy Using Triangular Cross Sectioned Copper Tool Electrode

Abstract

A case experimental research towards investigating aspects of Electro-Discharge Machining (EDM) on Inconel 718 super alloy using Copper tool electrode (of triangular cross section) has been delineated herein. Based on three controllable process variables viz. peak discharge current, pulse-on duration and gap voltage, experiments have been carried out to investigate their effects on Material Removal Rate (MRR); Surface Roughness (SR); Surface Crack Density (SCD) and White Layer Thickness (WLT) observed onto the top surface of the EDMed end product. Additionally, EDAX analysis has been carried out to investigate the extent of carbon enrichment that has been incurred onto the machined surface as affected during pyrolysis of the dielectric fluid whilst executing EDM operation. XRD tests have been carried out to compare metallurgical features (various phases/precipitates present in bulk of the matrix material, extent of grain refinement, crystallite size, crystallite strain, dislocation density) of the EDMed work surface with respect to ‘as received’ Inconel 718. Results, thus obtained, have also been compared to that of micro-hardness test data.