Parametric Study of Electro Discharge Boring of Inconel 718 with Radial Tool Movement Using Taguchi Method

Electro discharge machining is an unconventional machining process in which material is removed by spark erosion. In the present research work, EDM process has been used for carrying out boring operation of Ni based superalloy (Inconel 718). Boring operation has been performed by guiding and controlling the movement of tool electrode on radial orbital tool path. Experiments have been conducted using Taguchi’s method to obtain the influence of orbital and non-orbital parameters on material removal rate (MRR), tool wear rate (TWR) and surface roughness (Ra). ANOVA has been performed to identify the statistically significant parameters. It has been observed that all selected parameters are statistically significant in which peak current contributes 52.26% followed by flushing time i.e. 17.27% in determining the MRR. The peak current, pulse on time and orbital speed has been identified as significant parameters for TWR. The percentage contribution of peak current has been obtained maximum as 42.80% followed by pulse on time (38.48%) for TWR. The variation of surface roughness has been significantly affected by peak current, pulse on time, pulse off time and orbital speed. The peak current contributed about 80.21% followed by pulse on time about 15.03% for determining surface roughness. Estimation and confirmation experiments have been performed to verify the optimal combination of parameters.