Modeling and Spark Erosion Drilling Process Optimization of Inconel 718 Using RSM Technique

Electrical discharge machining with rotary tool is known as electric discharge drilling (EDD) which is being widely used for machining the difficult-to-cut materials like super alloy, ceramics and composite materials. Present research work has been introduced to find the impact of four influencing input factors discharge current (C), pulse off time (T-off), pulse-on time (T-on) and drill speed (S) on the response, tool wear rate (TWR), metal removal rate (MRR) and Centre line average value of surface roughness (R-a). The spark erosion drilling was performed on the Inconel 718 with rotating copper electrode. The major performances characteristics material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) are to be evaluated with consultation of Response Surface Methodology (RSM) techniques. The central composite rotatable design (CCRD) has been reported to plan the experimental design and developing the model for prediction of data within the range of investigation. ANOVA test was also carried out to check the adequacy for development of models. It has been evaluated that discharge current, T-on, and T-off have been found as most signifficant factors that effects on the performance measures. The models have 86.02, 84.29, and 83.15% values of correlation coefficient (R-2) for MRR, TWR and R-a whereas the adjusted R-2 (R-2 adj) are 73.80%, 70.55%, and 68.41% for MRR, TWR and SR, respectively.