International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 03 Issue: 04 | Apr-2016 www.irjet.net p-ISSN: 2395-0072 © 2016, IRJET | Impact Factor value: 4.45 | ISO 9001:2008 Certified Journal | Page 1316 Optimization of Electrical Discharge Machining Process Parameters Using Flushing and Drilled Tool Rahul Gupta 1 , Pooja Bibave 1 , Ashish Shelke 1 , Rohit Kesarkar 1 , Prasad Bari 2 , Santosh Chauhan 2 1 B.E Student, Dept. of Mechanical Engineering, FCRIT, Vashi, Maharashtra-400703, India 2 Assistant Professor, Dept. of Mechanical Engineering, FCRIT, Vashi, Maharashtra-400703, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Electric Discharge Machining (EDM) is a thermo- electric non-traditional machining process in which material removal takes place between a pair of electrodes which are submerged in a dielectric medium. In present study the effect of Flushing discharge and tool hole diameter on MRR has been studied along with current, voltage and spark on time. The optimization was done using Design of Experiments (DOE). It is observed experimentally that increase in flushing discharge increases the MRR. Also increase in tool hole diameter increases MRR up to a certain value and decreases with further increase in diameter. Key Words: EDM, Flushing, Dielectric medium, MRR, DOE. 1. INTRODUCTION Electro Discharge Machining (EDM) [1] is a non-conventional machining process which is more efficient than conventional machining process due to ease of machining of difficult-to machine materials with complex shapes. It is also used for machining the materials which are hard enough to cut by traditional processes. It has many applications in industries like aerospace, automobile, general engineering, etc. EDM performance is mainly dependent on factors like flushing discharge, pulse on time, current, voltage, tool geometry. Flushing [6] is the greatest key role which provides correct circulation of dielectric liquefied in any electrical discharge machining operation. If removed particles are not flushed thoroughly, they act as obstacles in the small gap between tool and work piece. Flushing is the procedure of presenting clean strained dielectric liquid into the spark gap. Fig-1.1 shows the basic principal of flushing. By scrutiny of the published research work, the paper addresses the issue that an alternate type of tool like hollow tube electrode may have a positive impact on MRR with low tool wear rate due to improved flushing conditions. Hollow tool is particularly useful for drilling holes with low tool wear rate. It was found that while machining the same length of Inconel718 with a solid tool it takes approximately 40% more machining time than taken by a hollow tool [7] . Hollow tool also helps in minimizing the dielectric fluid degradation. Consequently, the approach light is cost effective with higher yield, and reduced material and energy loss. The work will be carried out using Drilled tool varying the diameters [9] of the hole and finding the optimum combination of parameters and experimentally conform the results [3] . Fig -1.1: Flushing [10] 1.1 Experimental Setup The Experiment set was conducted on an EDM machine, CHMER 50-EZ using 16mm diameter copper tool [2] electrode and variable flushing discharge for studying the effect of flushing discharge on MRR. For studying the effect of tool hole diameter on MRR the tool was drilled by 4mm, 6mm and 8mm diameter. The experiment was conducted on EN-353 [7] steel using EDM-30 oil as dielectric. The properties of work piece and tool electrode are listed in the following table: Table -1.1.1: Properties of Cu Electrode [2] Property Description Density 8960 kg/m 3 Melting point 1083C Thermal conductivity 401 W/mK Electrical resistivity 1.673e-008 ohm Bulk modulus 137.8 GPa