Analyzing the Machining Effectiveness of EDM on Inconel 718 Using Copper and Graphite Electrode

Inconel 718 is a nickel-based super alloy that is well suited for applications requiring high strength and better wear resistance in a varying temperature environment. Owing to its higher strength, most of the conventional machining techniques fail to machine Inconel 718 material. Electric discharge machining was found to be a good alternative to the conventional techniques to machine such superalloys. In this paper, the machining characteristics of Inconel 718 were investigated using copper and graphite electrode. A mixed-level Taguchi L18 orthogonal array is chosen to conduct the experiments with varying process parameters like tool material, pulse on time (Ton), voltage (v), and current (I). Material Removal Rate (MRR), Tool Wear Rate (TWR), and Surface roughness (Ra) are the performance characteristics selected for evaluation. The developed model was found to be in good agreement and the Cu tool gives the best result. Keywords: Electrical Discharge Machining, Inconel 718, Taguchi L18 array; Optimization, MRR, TWR,