Investigation on the Machining of Inconel-718 Using EDM

Electrical discharge machining has gained significant amount of attention as it can deal with “hard materials” which otherwise exhibit poor machinability. One such hard material is Inconel-718, a nickel-based alloy which has material properties suited for a lot of critical engineering applications. In this paper, an optimization study to analyze the result of different combinations of process parameters, “current”, “pulse-on duration” and “pulse-off duration” on drilling of Inconel-718 is presented. To understand the effect of these parameters, design of experiments was done using Taguchi orthogonal array. The objective was to understand the parametric effect on the material removal rate (MRR) for the chosen range of machining process parameters. It has been found that “current” has the most significant impact on the response parameter (material removal rate). The study has also provided the combination for the largest possible material removal rate for the given set of process parameters based on the concept of larger the better optimality condition.