Investigation through novel tool-electrode feeding approach on electrochemical discharge machining of glass

Abstract

The electrochemical discharge machining (ECDM) process is a promising advanced machining process to remove material from electrically non-conductive materials like glass, ceramics, etc. Till now fabricating a channel with a high aspect ratio on the glass surface is a challenging job as the generated gas bubbles are escaped from the machining area without developing gas film and consequent discharges. In this study, two novel approaches of tool feeding such as side feeding and bottom feeding along with usual top feeding approach have been introduced to keep the gas bubbles at the tool-electrode tip so that the development of gas film and spark discharge are taken place uniformly at the machining zone. Tool-electrode feeding at the bottom surface and at the side surface of workpiece have been employed and compared with the usual top feeding tool-electrode at the top surface of workpiece. The concentration of aqueous sodium hydroxide electrolyte and the feed rate of tool are varied for experimental investigations. The side feeding of tool-electrode has been found as the most suitable feeding approach for ECDM process. During side feeding approach, the overcut of the machined channel has been reduced by 11% as compared to that of top feeding. Also, depth of the channel has been increased significantly during machining by side feeding and bottom feeding. The tool wear has been reduced more in case of side tool-feeding approach than other two tool-feeding approaches.