Available online at www.sciencedirect.com ScienceDirect Materials Today: Proceedings 4 (2017) 3043–3052 www.materialstoday.com/proceedings 2214-7853 ©2015 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of Conference Committee Members of 5th International Conference of Materials Processing and Characterization (ICMPC 2016). 5th International Conference of Materials Processing and Characterization (ICMPC 2016) Optimization of EDM process parameters for AlSiC- 20% SiC reinforced metal matrix composite with multi response using TOPSIS Avijeet Satpathy a , S Tripathy b , N Pallavi Senapati c , Mihir Kumar Brahma d a Student, ITER, S‘O’A University, Bhubaneswar, 751030, India b Assistant Professor, Mechanical Engineering Department, ITER, S‘O’A University, Bhubaneswar, 751030, India c M-Tech Student, ITER, S‘O’A University, Bhubaneswar, 751030, India d M-Tech Student, ITER, S‘O’A University, Bhubaneswar, 751030, India Abstract The present study analyses the effect of input parameters namely peak current (Ip), pulse-on-time (Ton), duty cycle (DC) and gap voltage (Vg) on the response variables material removal rate (MRR), tool wear rate (TWR), diametral overcut (Z) and surface roughness (SR) during the electric discharge machining of AlSiC metal matrix composite (MMC) using copper tool electrode. L9 orthogonal array was selected to conduct the experiments. Multi objective optimization has been done using a hybrid approach by combining principal component analysis (PCA) and technique for order preference by similarity to ideal solution (TOPSIS) to obtain the optimum set of input parameters. Microstructure analysis was carried out on the machined surface obtained from the optimal set using Scanning Electron Microscope (SEM) to investigate the surface modification on the workpiece. ©2015 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of Conference Committee Members of 5th International Conference of Materials Processing and Characterization (ICMPC 2016). Keywords: EDM; metal matrix composite; material removal rate; tool wear rate; diametral overcut; surface roughness; PCA; TOPSIS 1. Introduction Over the last few decades, aluminium based MMCs have been successfully applied in the military, automotive and aerospace industries due to their light weight, high strength, stiffness and resistance to high temperature. [1]. Al MMCs are difficult to machine as they contain hard and brittle reinforcements. High tool wear and high tool cost have been reported during conventional machining of these composites. [2]. Hence EDM is an optimal choice for machining such materials. EDM is a thermo-electrical process in which material removal occurs by a series of successive discharges between the tool and the workpiece separated by a dielectric medium. In this experiment, electric discharge machining is done on the workpiece material AlSiC-MMC (20%SiC reinforcement) by copper tool electrode. E-mail address: npallavisenapati@gmail.com