A study based on electrochemical discharge assisted by hollow electrode and micro-nano bubble to process transparent non-conductive brittle materials

Abstract

To overcome the difficult part of sapphire drilling, this research proposes two auxiliary processing. The first solution is investigating the influence of the addition of micro-nano bubbles to the original electrolyte. It is confirmed that the micro-nanobubble assists ECDM. For glass processing, the processing time using micro-nanobubble electrolyte is 31% faster than the processing time using ordinary electrolyte. As for the current response for the first 20 s, the average current intensity increased by 26.7%. Another method is to use hollow electrodes to absorb the processed slag and replenish the electrolyte during the processing. We use a high-speed camera to acquire images and current simultaneously and found that when using hollow electrodes, the time between the formation of a gas film and the generation of electric sparks in the way of replenishing the electrolyte is the shortest. The time of replenishing electrolyte is 34.5% faster than that of not replenishing. In addition, the thickness of the gas film is reduced by 54%. In addition, for the influence of gas film thickness and current value on processing efficiency. Finally, two auxiliary methods are combined to realize the feasibility of electrochemical discharge machining of sapphire. Compared with the case without auxiliary methods, the depth is increased by 3.8 times. When the voltage increases, the maximum depth reaches 440.8 μm.