Optimization of machining parameters of EDM while machining Inconel 718 for form tolerance and orientation tolerance

This paper demonstrates the effectiveness of optimizing multiple characteristics of electrical discharge machining (EDM) of Inconel 718 using copper electrodes having different shapes via Taguchi method-based Grey analysis. The modified algorithm adopted here is used successfully for both detraining the optimum settings of machining parameters and for combining multiple quality characteristic into one numerical value called Grey relational grade or rank. The essential parameters like peak current, pulse on time and pulse off time are chosen to conduct the experiments on multiple characteristics namely material removal rate (MRR), electrode wear rate (EWR), form tolerance namely straightness and orientation tolerance like perpendicularity and angularity. Then, ANOVA is used to find out the parameter which significantly affects the other parameters. The experimental results have shown that the machining performance on multiple characteristics in the EDM process is improved effectively through this approach.