Ultrasonic assisted electrochemical discharge milling of complex glass microstructure with high-quality

Introduction: With the rapid development of MEMS, the demand for non-conductive hard and brittle material microstructure is increasing. Electrochemical Discharge Machining (ECDM) is one of the most effective methods to machine non-conductive materials like glass and ceramics. However, in the milling process, the problem of discharge pits of different sizes and large thermal cracks caused by excessive discharge energy and heterogeneous energy distribution leads to low machining accuracy, poor stability and surface quality.Objectives: In order to solve the above dilemmas and improve the machining quality and stability, a newly developed micro Ultrasonic Assisted Electrochemical Discharge Milling (UAECDM) method is proposed in this paper.Methods: Firstly, a mathematical model is established to reveal the material erosion mechanism in the machining process. Secondly, the influence of ultrasonic vibration on gas film formation and discharge energy is analyzed by theory and simulation. Finally, the effects of ultrasonic amplitude and machining parameters on the quality of microchannels are experimentally studied and optimized by single factor optimization. The machining tech-nology of UAECDM is creatively proposed. Results: The experimental results show that adding ultrasonic assistance and using the optimized machining parameters can refine the film thickness, optimize the energy distribution and stabilize the current signal. With assistance of ultrasonic vibration and optimized parameters, a smooth micro channel with width of 118.9 mu m was fabricated, and its surface roughness was 0.23 mu m, which was 80.99 % declined from 1.21 mu m of ECDM. The successful fabrication of microchannel array, two-dimensional and three-dimensional complex glass micro-structures with surface roughness of about 0.2 mu m also proves the excellent machining ability of UAECDM.Conclusion: It is proved that UAECDM can effectively improve machining accuracy, stability and surface quality. UAECDM is a desirable method to fabricate micro-channel on glass and will have a very broad industrial application prospect in the future.