Optimization of Electric Discharge Machining of M2 Tool Steel Using Grey Relational Analysis

Abstract Tool steels are very difficult to machine by conventional machining processes owing to their high hardness value. Electric discharge machining (EDM) provides an easy method of machining such materials even by using a softer tool material. The present work aims to optimize the output parameters like metal removal rate (MRR), electrode wear ratio (EWR) and over cut (OC) with respect to the input parameters like tool rotation speed, voltage and spark time during electric discharge machining of tool steel M2 using Grey relational analysis with a L9 orthogonal array. The electric discharge machining was done by a rotary brass electrode of 18.8 mm diameter to make 4 mm deep blind holes on tool steel M2 work-piece using EZNC EDM machine. The analysis of variance (ANOVA) of the gray value was also performed. The electrode rotation speed was found to affects the output parameters most followed by voltage and the spark time.