Simulation and Experimental Study on Micro Electrochemical Drilling with Ultra Short Pulse Voltage by using High-speed Spiral Electrode

Background: The fabrication of Micro-holes in hard machining materials is always difficult according to recent patents. The electrochemical drilling process is a good selection for the fabrication of Micro-holes. Methods: In this paper, an electrochemical drilling process for fabricating Micro-holes with high efficiency is introduced, and simulation of the gap electric field and the gap flow field is carried out. Firstly, the model of ultra short pulse gap electric field is established, the shape change of the anode workpiece surface in the electric field is analyzed and predicted based on the simulation of the drilling with ultra short pulse voltage. Then, the numerical simulation of the gap flow field is simulated by CFX with the increase of the electrode rotating speed. Finally, the simulation results are verified by the experiments. Results: The removal direction and rate of a point on the surface of the workpiece with ultra short pulse voltage was derived. The shape change of the anode workpiece surface with ultra short pulse voltage was simulated. The distribution of water vapor and the velocity vector graph in micro machining was obtained. A series of Micro-holes was machined successfully, the diameter of the Micro-holes was less than 200μm. Conclusion: The ultra short pulse voltage can greatly improve the machining localization. The gas film with good insulation effect around the electrode increases rapidly, which can reduce the taper of the Micro- holes significantly. The experiment results prove that the micro electrochemical drilling for fabricating Micro-holes has a huge potential and a widespread application prospect.