Multi-objective optimization of vibration assisted electrical discharge drilling process using PCA based GRA method

Abstract

Nowadays, quality and cost of the biomedical products are the key issues for the medical industries to sustain in the global market. Such industries are highly concerned with the machining and high-quality finishing of products manufactured by biocompatible materials. The utility of medical products manufactured by biocompatible materials are increased day by day. In order to that, industries are looking for the advanced technologies for machining such materials and also focusing on optimizing the cost of product without compromising in quality. In view of the above-mentioned problem, Hybrid machining processes are becoming the best possible solution for improving the MRR and surface finish. In present research, a hybrid approach of Vibration Assisted Electrical Discharge Drilling (VA-EDD) is used for processing of Titanium alloy. This paper presents a multi-objective optimization of the VA-EDD process for Ti-6Al-4V to provide higher MRR with a good surface finish. The experiments were conducted using a face-centered central composite design (CCD) of response surface methodology (RSM). The machining characteristics, MRR and SR have been optimized simultaneously by using Principal Component Analysis (PCA) based Grey Relational Analysis (GRA). The VA-EDD process was optimized for getting the optimal levels of process parameter for higher MRR and lower Ra value. The results reveal that the PCA based GRA approach have acquired the setting of optimal process parameters for the VA-EDD process as pulse current (Ip) = 15A, pulse on time (Ton) = 120 µs, pulse off time (Toff) = 15 µs, tool rotation (rpm) = 1200 rpm, and vibration amplitude = 8 µm.