An Experimental Study on Parametric Optimization for Material Removal Rate and Surface Roughness on EDM by using Taguchi Method

Abstract

The objective of this research study is to investigate the optimal process parameters of EDM(Electric Discharge Machining) on Aluminium work piece with Copper as a tool electrode. The effect of various process parameters on machining performance is investigated in this study. The input parameters considered are Discharge Current, Pulse ON time, Flushing Pressure and Polarity. The paper reveals their effect over two different machining responses i.e., Material Removal Rate (MRR) and Surface Roughness (SR). The Taguchi method was used to formulate the experimental layout, ANOVA method for the analysis of the effect of input process parameters over the responsesand S/N ratio along withAverage performance graphs were carried out for the optimal setting of the parameters. The optimal conditions for MRR based on larger-the-better characteristics was obtained at A2B1C2D1 i.e.Discharge Current at 16A, Pulse- ON time at 463μs, Flushing Pressure at 10kgf/cm2 and Normal Polarity. Similarly for Surface Roughness based onsmaller-the-better characteristics,the optimal settingwas obtained at A1B1C2D2 i.e. Discharge Current at 8A, Pulse ON time at 463μs, Flushing Pressure at 10kgf/cm2 and Reverse Polarity. Both these optimal settings were validated by S/N ratio and Average performance graph.From the analyses it was experienced that in case of MRR the polarity is the most significant factor followed by current, whereas for surface roughness the current was found to be the only significant factor.