Research On Micro-electrochemical Milling Technology Based On Online Preparation Of Disc Electrode

Microstructures and micro-parts are the major component of MEMS,they play an important role in some devices.Machining accuracy and surface quality of microstructures and micro-parts have a significant impact on device performance.Aiming at the difficulty in making tool electrodes and poor processing quality during electrolytic milling,the research on micro-electrolysis milling technology based on on-line preparation of disc-shaped tool electrodes was carried out.High precision on-line preparation of disc tool electrodes by micro-WEDM on the same machine tool is realized.Based on the micro-electrochemical milling system,in-situ micro-electrochemical milling of micro-structure is realized.The construction of a micro electrolytic milling system was carried out on the original micro-EDM wire cutting machine.LabVIEW upper computer control interface and MCU program of the control system are designed.A high-frequency narrow-pulse electrolysis power supply was produced with a minimum pulse width of 60 ns,a maximum voltage of 15 V,and a maximum current of 500 mA.The method of average voltage detection is used to detect the average voltage of the gap in electrolytic machining,and the function of short circuit turn back of the electrode is realized.The dynamic change of the shape of the workpiece during the electrolytic machining process was simulated.Apply high frequency pulse voltage in secondary current model,the simulation results are similar to the shape profile of the actual machined workpiece,and the dimensional accuracy deviation is controlled within 10%.The simulation of the electrolytic machining process under the coupling of multiple physics is carried out.The results show that the secondary electrolysis strength of the machined surface can be reduced and the processing quality can be improved when the direction of the flow field is opposite to the direction of the electrolytic milling feed of the electrode,and the test is verified.The design of the multi-blade disc tool electrode was carried out by using the two-dimensional simulation model.It was found that when the blade length was 900 ?m,the surface of the workpiece corresponding to the blade bottom will not undergo significant electrochemical reaction.A single factor test of micro electrolytic milling was performed using a square electrode with a blade width of 170 ?m.A microgroove with a groove width of 254 ?m,sharp edges and good surface quality is processed using the optimized process parameters.The electrochemical milling experiments of micro grooves with different shapes were carried out by using the prepared square,sharp and multi-edged electrodes.The results show that when the blade width is reduced,the single-edge gap of electrolytic machining can be reduced and the machining accuracy can be improved.When the electrode blade length is 900 ?m,the surface quality of the workpiece surface corresponding to the blade edge of the three-blade electrode can be ensured.Typical array structures with different slot widths are fabricated by using single-edged square electrodes with different edge widths(170?m,90?m).The results show that the dimension consistency deviation of groove width is 3.11% when the edge width is 170 ?m and 1.89% when the edge width is 90 ?m.When the edge width is small,the size consistency of the microgrooves in the array structure is good,and the shape accuracy of the square convex platform formed by the array microgrooves is good.