To Determine the Effect of Machining Parameters on Surface Roughness of EN 31 Stainless steel using EDM

Abstract

The objective of the work carried out is to study the effect of EDM uon the Surface Roughness. The experiments were conducted by using the Electric Discharge Machine, model ELEKTRA (EMS 5535) is located at CITCO-IDFC TESTING LABORATORY, CHANDIGARH, INDIA. Surface Roughness test was performed at Institute for Auto parts and Hand Tools Technology, Ludhiyana. The polarity of the electrode was set as positive while that of work piece was negative. The dielectric fluid used was EDM oil (Sp. Gravity – 0.763). The machine also has the capability to vary peak current, pulse on time, pulse off time etc. Considering the capability of machine and the output required for the experimentation, peak current, pulse on time and pulse off time were decided to be taken as the variable and all the other factors have to be kept fixed. Mitutoyo Surface Roughness Tester instrument is used for testing roughness of the specimens. To obtain the desired results with minimum possible number of experiments, Taguchi method has been employed. Using Taguchi L27 Orthogonal Array has been selected and the experiments have been designed. After performing the experiments, results of the experimentation have been analyzed and graphs for effect of various input variables upon output characteristics and for Signal-to-noise ratio have been studied and discussed using ANOVA (Analysis of Variance). Also, the optimum combination of input variables has been determined which will give the best results for output parameters using Signal-to-noise ratios.