Experimental Investigation for Micro-Machining of Borosilicate Glass using Ultrasonic Assisted Rotary Electrochemical Discharge Machining (UA-RECDM) Process

Abstract Electrochemical Discharge Machining is an advanced micro-machining process for machining of conductive as well as non-conductive hard and brittle materials i.e., glass, ceramic and silicon wafer etc. The present work explores the machining of glass using in-house developed novel Ultrasonic Assisted Rotary Electrochemical Discharge Machining (UA-RECDM) setup. The setup has specialised features which includes ultrasonic vibrations to tool electrode and rotary motion to workpiece. Experiments were conducted using one factor at a time approach (OFAT) approach by varying tool feed rate, amplitude of vibrations and rotation of workpiece as process parameters. The quality of the machining output was evaluated by observing two key parameters: overcut and circularity of the hole. It was observed that as the workpiece rotation speed increased from 40 RPM to 60 RPM, the overcut in the machined samples decreased from 181.378 µm to 163.564 µm. The rotary motion of workpiece causes seeping action of the electrolyte at hydrodynamic regime and results in thin gas film formation & stabilized discharging phenomenon. The morphology of machined hole exhibits better circularity, low HAZs, minimum micro-cracks and smooth edges at periphery due to stable discharge formation.