Analysis of Process Parameters in Wire EDM with NITINOL Shape Memory Alloy using Multi Objective Grey Relational Grade

The position of traditional machining process are taken by non-traditional machining processes because of  increasing demands of high surface finish and machining of complex shape geometries,. Wire EDM is one of the non-traditional machining processes. Surface roughness and material removal rate are of most importance in the field of machining processes. This paper gives brief description of the Grey relational theory and Taguchi optimization technique, in order to optimize the cutting parameters in Wire EDM for NITINOL shape memory alloy. The objective of optimization is to attain the minimum surface roughness and the best surface quality along with that higher material removal rate. In this present study NITINOL shape memory alloy is used as a work piece, brass wire of 0.25mm diameter used as a tool, orthogonal array has been used. The input parameters selected for optimization Peak current, pulse on time, pulse off time, wire feed, and wire tension,also other parameter are kept constant. For each experiment material removal rate and surface roughness was determined. With the help of multi objective optimization technique grey relational theory, the optimal value is obtained for material removal rate and surface roughness and by using Taguchi optimization technique. Additionally, the analysis of variance (ANOVA) is used for identifying the most affecting parameter factor.