JMS_V4_N4_RP1 Govindan Puthumana Journal on Material Science 2347–615X 4 4 1 9 Micro Electrical Discharge Machining, Response Surface Modelling, Material Removal Rate, Tool Wear Rate, Input Factors, Optimization Inconel 718 is a corrosion-resistant and high strength nickel-based alloy with wide range of applications, including components for cryogenic tankage, liquid fueled rockets and casings for aircraft engines. The material is characterized by high hardness, high temperature strength, low thermal conductivity and high strength causing it extremely difficult to machine. Micro-Electrical Discharge Machining (Micro-EDM) is a non-conventional method that has a potential to overcome these restrictions for machining of Inconel 718. Response Surface Method (RSM) was used for modelling the tool Electrode Wear Rate (EWR) and Material Removal Rate (MRR) with the input factors, such as voltage (V), peak current (I ) and pulse on-time (T ). The RSM analysis of variance results show that the main input factors’ pulse off-time and p on voltage are significant in controlling the tool electrode wear rate at 95% confidence level. An increase in voltage from 30 to 45 V and pulse on-time from 1 to 3 μs causes a linear decrease in EWR by 35%. Using response surface modeling, a 3 3 minimum EWR of 12.3184 μm /min and a maximum MRR of 37.2151 μm /min is obtained at a current of 1.07 A, pulse ontime of 4.44 μs, pulse off-time of 4.06 μs and voltage of 60 V. January – March 2017 Copyright © 2017 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=10362