ELK Asia Pacific Journals – Special Issue ISBN: 978-81-930411-8-5 DESIGN AND EXPERIMENTAL INVESTIGATION OF ELECTRO CHEMICAL DISCHARGE MACHINING OF TINY GLASS Rajnish Saxena, Basanta Kumar Bhuyan Mechanical Engineering Department, Faculty of Engineering & Technology Manav Rachna International University, Faridabad, India Email: rajnish.fet@mriu.edu.in Abstract— Electro Chemical Discharge Machining (ECDM) is a recent innovative hybrid machining process which is combining characteristics of Electro Chemical Machining (ECM) & Electro Discharge Machining (EDM) and more suitable for non conductive engineering ceramic materials, such as ceramics, zirconium oxide, composites and silicon nitrides. In the present work, design and development of tabletop ECDM setup has been successfully completed for machining the borosilicate glass work piece. Furthermore the influence of input parameters such as applied voltage, electrolyte concentration and inter-electrode gap on output parameters like Material Removal Rate (MRR) of ECDM process. It has been observed during experiments applied voltage increases with increase of MRR but inter-electrode gap decreases with increase of MRR. It has also been obtained electrolyte concentration increases up to 250g/l with increase of MRR, beyond that values it decreases. Moreover, some preliminary observations have been investigated during machining of borosilicate glass using Scanning Electron Microscope (SEM). Keywords— ECDM; EDM; ECM; Borosilicate glass; SEM I. INTRODUCTION The demand of non conductive engineering ceramic materials such as Aluminum oxide, Zirconium oxide has increase day by day with the major application in mechanical, electrical, optical system or in all mechatronics system. Tinny glasses are widely used due to its unique properties like chemical resistance, transparency, non conductive very tough. Tinny glass has wide industrial applications in scientifically application, jewelry industry, medical appliance, aero space, auto mobiles, and chemical laborites. In today’s scenario every organization try to increase machining quality and reduce other parameter like cost so improve the performance and get maximum profitability, so to achieve this a new hybrid process called Electro Chemical discharge machining (ECDM) process used. ECDM process is best suited for Composite, non conductive, ceramic material, micro channel, micro gear, and also best utilization of process in Jewelry industry, Aeronautical industry and all industries where precision and accuracy required. Several researchers have been studied experimentally and theoretically the ECDM process. Laio et al [1] performed experiment and found that if the current density is increased, and there is more bubble release around the electrode as compared with that when machining in the electrolyte without SDS. Jawalkar et al. [2] found that the applications of ECDM on soda-lime glass for making shallow holes, using design of experiments, and also discussed applied voltage is the most influencing parameter. Cheng et al .[3] stated that Electrochemical Discharge Machining (ECDM) is an alternative spark-based micro-machining method for producing micro-holes and micro channels in non- conductive hard and brittle materials. Xuan et al. [4] investigated polycrystalline diamond (PCD) tools is used to overcome the rough surfaces that are generated by sparks in ECDM, also found that the grinding process under PCD tools reduces the surface roughness of ECDM structures from a few tens of a μm to 0.05 μm R a . K. Nguyen et al [5] stated that the ECDM characteristics according to machining parameters, such as electrolyte level, electrolyte concentration, pulse voltage, offset pulse voltage, pulse on-time, pulse off-time, and tool feed rate. Based on the investigation of the machining conditions, micro structures, including micro grooves and columns, were machined on quartz material. K. Shanmukhi et al [6] developed the mathematical model using RBFNN during micro drilling of ECDM of silicon nitride ceramics work piece of ECDM process. They established the model with Input parameters such as applied voltage, electrolyte concentration and inter-electrode gap, and out put parameters material removal rate (MRR), radial overcut and heat affected zone. and also optimize the process parameter using genetic algorithm (GA) and particle swarm optimization (PSO) methods, finally they validated the experimental result GA-trained RBFNN (GA-RBFNN) and PSO-trained RBFNN (PSO-RBFNN) with the experimental test cases, and observed that PSO-RBFNN is better than GA- RBFNN. Some researchers also investigated that overcut is a major reason for the dimensional deviations, especially during high aspect ratio micromachining in ECDM and is explained with an analytical model and found that effect of concentration on the overcut, some researchers also develop analytical model of the gas film, involving bubble growth and departure on electrode, gas film evolution, and electrolysis characteristics. Experiments were carried out to compare models to the actual discharging phenomenon. High speed camera imaging demonstrated the formation of a gas film on the tool electrode. The range of thickness of gas film found in experiments indicated good consistency with the range of film thickness estimated from analytical models .Experiments on critical voltages and currents further revealed the characteristics of the gas fil The model considers the thermal effects on material removal for ECDM assuming a high- temperature chemical etching mechanism for the material removal. It describes the effect of electrolyte concentration as well as machining time on material removal. C.Wei et al[8] on their work develop a finite element based model for ECDM drilling in discharge regime. Material removal subjected to a single spark was simulated using finite element method. The drilling depth evolution in discharge regime was predicted. The model predictions were compared with