Multi-objective Optimization of EDM and Powder Mixed EDM for H-11 Steel

Abstract

AbstractElectrical discharge machining (EDM) is a benchmark method for material removal from workpiece in aerospace, automotive, dies and mold making industries, etc. To enhance the process performance of EDM, powder mixed electrical discharge machining (PMEDM) is being expansively put to use by practitioners for improving the performance of the process while maximizing the efficiency and enhancing the quality of the surface. The present study aims at investigating the influence of “concentration of powder (Cp), peak current (Ip), on time of spark (Ton), duty cycle (DC), and gap voltage (Vg) on responses like rate of material removal (MRR), rate of tool wear (TWR), wear ratio of the electrode (EWR), and roughness of the surface (SR)” for EDM and PMEDM of H-11. Taguchi’s experimental design technique is used along with technique for order of preference by similarity to ideal solution (TOPSIS) followed by gray relational analysis (GRA) to estimate the performance of the process. Graphite powder of size less than 53 µm has been used as the additive for experiments conducted with L27 orthogonal array. Electrolytic copper has been taken as the tool electrode for conducting the experiments. An improvement of 0.115631 and 0.14211 in preference value is observed while conducting the confirmatory experiments with the use of TOPSIS and GRA. The optimal set of input parameters from TOPSIS is achieved at Cp = 6 g/l, Ip = 3 A, Ton = 200 µs, DC = 80%, and Vg = 50 V and from GRA as Cp = 6 g/l, Ip = 3 A, Ton = 150 µs, DC = 80%, and Vg = 30 V.KeywordsElectric discharge machiningPMEDMGray relational analysisTOPSIS