Numerical and experimental investigation of glass micromachining using ultrasonic-assisted electrochemical discharge machining

This paper addresses challenges in debris removal and electrolyte replenishment during the electrochemical discharge micromachining (ECDM) of glass. The study presents a comprehensive numerical and experimental study of glass micromachining using ultrasonic-assisted electrochemical discharge machining (UA-ECDM). A finite element method (FEM)-based numerical model was developed to simulate the effects of ultrasonic vibrations on electrolyte flow and debris movement. The simulation results reveal that increasing ultrasonic amplitudes from 5 µm to 10 µm improves the electrolyte flow velocity two times at the microhole bottom. Additionally, ultrasonic vibration enhances debris distribution, shifting it towards the periphery of the microhole, thus improving the electrochemical discharge conditions. Experimentally, glass micromachining was performed at different ultrasonic amplitudes (0, 5, 8, and 10 µm). The results demonstrate that ultrasonic vibrations increase machining depth, reducing hole taper as a result of improving electrolyte circulation, correlating with the simulation result. A 3 × 3 array of holes was successfully fabricated on a glass substrate with a depth of 835 µm, confirming the feasibility of UA-ECDM for microhole drilling. This study confirms that UA-ECDM improves electrolyte circulation, enhancing electrochemical reactions at the tool-workpiece interface and increasing machining depth.