Multi objective optimization of wire-electrical discharge machining of stellite using Taguchi – Grey approach

Abstract

Wire Electrical Discharge Machining (WEDM) is one of advanced method of machining conceived from the concept of Electrical Discharge Machining. Unconventional method of material removal processes have been developed to overcome the difficulties in making of complex shapes in any electrically conductive work material by conventional machining methods. Stellite is a difficult to machine superalloy and extensively used in wear environments where its low friction coefficient minimizes the risk of seizing and galling. It possess good strength and lower thermal diffusion results in decreased tool life and poor machinability by conventional methods of machining. The present work details the multi objective optimization of WEDM process parameters by Taguchi-Grey approach. The experimental runs are planned by Taguchi's design approach and Taguchi's approach single objective optimization technique was employed for attaining the best possible process parameters combination for obtaining better machining performance. The experiments have been performed by considering the process parameters such as pulse on time, pulse off time and wire tension at three various levels. The ascendency of process variables are determined by ANOVA analysis. Taguchi - Grey methodology has been adopted for the WEDM process and optimum process parameters are determined for attaining improved multi performance characteristics.