Ultrasonic-assisted electrochemical discharge grinding and broaching for machining quartz square microholes

A novel hybrid technology that ultrasonic-assisted electrochemical discharge grinding combined with in-situ ultrasonic broaching was used to process an array of square microholes on quartz glass. Diamond abrasive particles were directly added to the electrochemical discharge electrolyte to simultaneously perform electrochemical discharge machining and grinding. Because the diamond abrasive particles were added to the electrolyte, it could be used for both processes and replacing the slurry or electrode was unnecessary. This method removes material through simultaneous melting, etching, and impact grinding. The proposed method was successfully used to machine a 2 × 2 array of square microholes in quartz glass. The hole inlet size was 20 μm, and the difference between the maximum and minimum average size of the array holes was only 6 μm. After the final step of ultrasonic vibration broaching using the same electrolyte, the difference between the maximum and minimum average inlet size was reduced to 3 μm, and the hole taper angle was 1.77°.