SUSTAINABLE SURFACE CHARACTERIZATION AND PERFORMANCE ANALYSIS OF VIBRATION-ASSISTED EDM OF INCONEL 718

Sustainable vibration-assisted electrical discharge machining (VA-EDM) has received much interest as a modern machining approach to nickel-based superalloys such as Inconel 718, due to its ability to address the inherent shortcomings of conventional EDM, such as low material removal rate (MRR) and poor surface integrity. The current work achieved the design of a new vibration-assisted EDM system with an improved flushing mechanism that will improve the debris removal rate and stabilize the discharge plasma channel. The influence of the main process parameters, i.e., the peak current and pulse-on time, on machining performance, were evaluated in a systematic manner. An extensive surface integrity evaluation was conducted, including white layer thickness, surface roughness, and microcrack density. Va-EDM process showed a high decrease in the thickness of recast layer and crack propagation due to better circulation of dielectric and even distribution of spark based on tool vibration. Moreover, the machined surfaces exhibited low roughness values in comparison to conventional EDM, which implies a higher quality of surfaces. The results confirm that thermal gradients and re-solidification behavior can be successfully controlled through vibration-assisted discharges, leading to better surface attributes and machining stability of Inconel 718.