Optimization of Process Parameters of Wire Electric Discharge Machining on AISI 4140 Using Taguchi Method and Grey Relational Analysis

Abstract

Abstract In this study main focus is on the minimized value of the response variables such as surface roughness and kerf width by setting process parameters of wire electric discharge machining at the optimum level. Single objective optimization is done by using Taguchi L9 orthogonal array and for multi-objective optimization grey relational analysis is used. For experimentation pulse on time (Ton), pulse off time (Toff), servo voltage (SV), wire feed (WF) those process parameters are to be varied while other parameters such as input current (Ip), gap voltage (V), water pressure (WP), wire tension (WT) and servo feed (SF) those parameters are taken as fixed parameters. The major application of AISI 4140 material is in the defense due to its high hardness and high strength. Literature review available on wire electric discharge machining of AISI 4140 is very scanty because of that reason AISI 4140 material is taken for this study. Regression analysis and analysis of variance (ANOVA) find out with help of Minitab software. ANOVA helps to identify the major influencing process parameter for surface roughness and kerf width. From ANOVA major influencing factors for surface roughness, kerf width is the pulse on time and servo voltage respectively. Result analysis shows that for single objective optimization using Taguchi method gives decrement in surface roughness, kerf width individually are 15.65% and 19.35% respectively. In the case of grey relational analysis decrement of surface roughness, kerf width simultaneously at the optimal condition as compared to the initial condition is 9.39% and7.62%.