Electro-Discharge Machining of Super Alloy Inconel 718: Emphasis on Material Removal Efficiency and Surface Integrity of the End Product

Abstract

A case experimental research towards investigating aspects of Electro-Discharge Machining (EDM) on Inconel 718 super alloy using Copper tool electrode 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 Material Removal Rate (MRR); Surface Crack Density (SCD) and White Layer Thickness (WLT) appeared onto the top surface of the EDMed end product. Additionally, EDAX analysis has been carried out to investigate the extent of carbon enrichment onto the machined work surface as affected during pyrolysis of the dielectric fluid during execution of EDM operation. XRD tests have been carried out to compare metallurgical data (viz. various phases/precipitates present in bulk of the matrix material, extent of grain refinement, crystallite size, and dislocation density) of the EDMed work surface as compared to ‘as received’ Inconel 718. Results, thus obtained, have also been compared to that of micro-hardness test data.