Multi response optimization of process parameters in wire EDM of D2 steel using TOPSIS technique

Abstract

newlineWire electric discharge machining is a thermo-electrical method where material removal was done by a series of sparks among the metal and electrode (tool) broken up by a thin film of dielectric fluid which is regularly fed in the machining zone to wash out the waste particles. A numerically controlled system is used to get the required shape and accuracy. WEDM contribute a major share in the manufacture of complex-shaped moulds, dies, and irregular parts used in almost all industries like aerospace, automobile etc. This process is mainly used for parts having close tolerances, complex shapes, and difficult to work metals. So, to select the optimum input machining parameters in WEDM is a vital task. If it fails to get optimum parameters then it may cause serious problems namely wire breakage, work surface damage and short circuiting of wire. newlineIn this work experiments are conducted by using three different wire electrodes namely Brass, Coated copper and Annealed copper wire electrode and the analysis is made based upon the tool material. Several experimentations are made to find the best Surface Roughness (SR), Kerf width, Metal Removal Rate (MRR) and Wire Wear ratio (WWR) are key performance features of the EDM. With Input current (IP), Pulse duration(Ton and Toff), wire tension, wire feed and Spark set voltage(SV) were picked as the input process factors, because for industrial application many machinists are choosing these input parameters and other is constant and pick under specific requirements only. newlineThe material used in this work is D2 steel which is an air hardening, high-carbon, high-chromium tool steel. It has high wear and abrasion resistant properties. It is heat treatable and will offer a hardness in the range 55-62 HRC, and is machinable in the annealed condition. D2 steel shows little distortion on correct hardening. D2 steel s high chromium content gives it mild corrosion resisting properties in the hardened condition. Typical applications for D2 Steel are Stamping or Forming Dies, Punches,