Machining Characteristics of Electro Discharge Machining on NIMONIC 80A by Response Surface Methodology

The paper investigates the effect of different machining parameters such as Current (A), Pulse ON time (T_on) and Pulse OFF time (T_off) of the Die-sink EDM process on NIMONIC 80A which influence the three major machining characteristics: Material Removal Rate (MRR), Tool Wear Rate (TWR) and Radial overcut (ROC). The experiment is executed and analysed as per Box Behnken Design (BBD) of Response Surface Methodology (RSM). After conducting the experiments, Analysis of variance (ANOVA) and optimization using desirability function were performed. Regression equation was developed to show a relationship of the influences of machining parameters on characteristics. This research results show that Current and Pulse ON time are the main important parameters for MRR and the Current is a major parameter for TWR and ROC. The optimize parameters where highest value of MRR and lowest value of TWR and ROC is Current 3 A, Pulse ON time 900 µs and Pulse OFF time 51 µs with the desirability value 0.988.