Paper Title
Optimization Study of Machining Parameters of EDM for D3 Tool Steel using Grey Relational Method

Abstract
This paper reports the influence of machining parameters viz discharge current, gap voltage, pulse ON and OFF time, on the optimality of multiple response parameters like material removal rate (MRR), tool wear rate (TWR) and surface roughness in EDM machining of AISI D3- High Carbon/High Chrome Tool Steel specimen using Copper and Brass electrodes by adopting Taguchi’s L9 Orthogonal Array design matrix in conjunction with Grey Relational Analysis method. Three levels were considered for each of the four control factors for nine experimental run and subsequent analysis of multiple responses. A hole of 20mm diameter and 0.5 mm depth was produced by EDM process after obtaining experimentation matrix. It was reported that all the response factors were significantly influenced by the chosen control parameters (or factors). In the present case the optimal parameter combination determined was A1-B3-C3-D3 for both electrodes i.e. pulse current at 16 A, pulse ON time at 75 μs, pulse OFF time at 9μsand gap voltage at 40 volt. Copper electrode was recommended over Brass owing to superior deposition characteristics. Keywords - Taguchi’s Design of Experiments, EDM, Grey Relational Analysis, D3 Tool Steel.