An Investigation into Laser-Assisted Electrochemical Discharge Machining of Transparent Insulating Hard-Brittle Material

Electrochemical discharge machining (ECDM) and laser machining are emerging nontraditional machining technologies suitable for micro-processing of insulating and hard-brittle materials typified by glass. However, poor machinability of glass is a major constraint, which remains to be solved. For the micro-grooves processed by ECDM, the bottom surface is usually uneven and associated with protrusion structures, while the edges are not straight with obvious wave-shaped heat-affected zones (HAZs) and over-cutting. Besides, the cross section of the micro-grooves processed by the laser is V-shape with a large taper. To solve these problems, this study proposed the laser-assisted ECDM for glass micro-grooving, which combines ECDM and laser machining. This study compared morphological features of the single processing method and the hybrid processing method. The results show that ECDM caused cylindrical protrusions at the bottom of the microgrooves. After processing these micro-grooves by laser, the cylindrical protrusions were removed. However, the edge quality of the microgrooves was still poor. Therefore, we used the laser to get microgrooves first, so we got micro-grooves with better edge quality. Then we use ECDM to improve the taper of microgrooves and the cross-sectional shape of the microgrooves transformed from a V-shape to a U-shape.