Optimization of micro milling electrical discharge machining of Inconel 718 by Grey-Taguchi method

The optimization of micro milling electrical discharge machining (EDM) process parameters of Inconel 718 alloy to achieve multiple performance characteristics such as low electrode wear, high material removal rate and low working gap was investigated by the Grey-Taguchi method. The influences of peak current, pulse on-time, pulse off-time and spark gap on electrode wear (EW), material removal rate (MRR) and working gap (WG) in the micro milling electrical discharge machining of Inconel 718 were analyzed. The experimental results show that the electrode wear decreases from 5.6x10(-9) to 5.2x10(-9) mm(3)/min, the material removal rate increases from 0.47x10(-8) to 1.68x10(-8)mm(3)/min, and the working gap decreases from 1.27 to 1.19 mu m under optimal micro milling electrical discharge machining process parameters. Hence, it is clearly shown that multiple performance characteristics can be improved by using the Grey-Taguchi method.