Optimising Parameters for Dry EDM Machining of Inconel 800 Through OFAT Approach

Abstract

The paper presents an experimental investigation and optimization of process parameters while performing Dry EDM of Inconel 800, Superalloy. The process parameters viz, Discharge current, Gap Voltage, Pulse on-time, Pulse off-time, Tool rotation, Air flow rate are selected as the initial investigations, and their levels are chosen to finalize the optimized parameters and levels for main experimentation. Inconel 800 a supernally is work material in this study. Five levels of each parameter are selected for trials. The impact of parameters against the responses viz, Material Removal Rate, Tool Wear Rate Surface Roughness are recorded for all five settings of levels. The results so obtained are plotted for each parameter, It was found that the discharge current at parametric settings of 8A, 12A, 16A, Gap Voltage at parametric settings of 40V, 50V, 55V, Pulse on-time at parametric settings of 60µs, 90µs, 120µs, Pulse off-time at parametric settings of 30µs, 60µs, 90µs, Tool Rotation at parametric settings of 120N, 160N, 240N and Air flow rate at parametric settings of 15 l/min, 20 l/min, 25 l/min gives better results in improving the responses. Scanning Electron Microscopy was also performed to investigate the effects of parameters on the machined surface of Inconel 800. A better surface with minimum cracks was produced as compared to conventional EDM at the same parametric settings.