This paper investigates spark electrical discharge machining (EDM) on super alloy Inconel 750. The tool used is copper electrode. The process performance is measured in terms of material removal rate, tool wear rate and also surface roughness (Ra). The input parameters like current, pulse-on time and pulse-off time are varied for each reading. Readings are taken as per Box Benhken experimental design. The tool wear and material removal rate are measured by using weight reduction method. Surface roughness is measured using surface roughness tester (MahrSurf GD120) machine. The result shows that the MRR is directly proportional to the current. While tool wear rate is highly affected by current variation and low surface roughness is obtained at low current levels. When pulse on time and current are kept constant the MRR changes according to pulse off time. Using Minitab software quadratic regression equations denoting relation between various parameters are obtained. Optimum levels for the process parameters for achieving high MRR, low TWR and low surface roughness (Ra) are studied.
