Parametric Optimization of Performance of EDM on Alloy Steel AISI 4147 using Taguchi Approach

Abstract

Electric discharge machine is a unconventional machining process of those hard materials that are difficult to machine such as heat treated  tool steels, composites, super alloys, ceramics, carbides, heat resistance steel being used in die and mould making industries, aero space, automobile, casting and  nuclear industries. The present experimental research for parametric optimization of EDM studies the process parameters that are affecting the machining performance and productivity of EDM. A combined approach is used for the optimization of parameters and performance characteristics based on Taguchi method. The design of experiments is based on Taguchi’s L9 orthogonal array. The response table and response graph for each level of machining parameters are obtained from Taguchi method to select the optimal levels of machining parameters. In the present work, the machining parameters are current, pulse on time and voltage which are optimized for maximum material removal rate (MRR), minimum tool wear rate (TWR) and minimum hole enlargement during electro discharge machining of Alloy Steel AISI 4147 as work piece and copper as electrode. Analysis of Variance is also used to find out variable affecting the various responses mentioned above. Finally, the results show that the MRR, TWR and hole enlargement are mainly affected by current and pulse on time. Voltage is the least affecting parameter for MRR, TWR and hole enlargement.