Micro Electrochemical Machining Technology For Flexible Parts Of Some Type Of Accelerometer

With the rapid development of micro/nano technologies, micro electrochemical machining (micro-ECM) technology has become an important aspect of advanced manufacturing technologies. Micro-ECM can machine micro hard-to-cut metal parts which are difficult to be machined with traditional machining methods. To solve the difficult problems (such as cutting difficulty because of hardness of elastic material, forming difficulty because of micro structure size, etc.) of machining thin flexible parts of some type of military accelerometers, micro-ECM technology for micro rectangular groove and trapezoid structure of flexible parts has been studied. This study plays an important role to solve the machining difficulties of micro elastic-material parts and to prompt the development of Micro-ECM technology.On the basis of theoretical research of micro-ECM, the composition of elastic material 3J21 is analyzed and appropriate electrolyte for 3J21 is selected. To study the effect of process parameters (machining voltage, feed rate, pulse width, electrolyte concentration, etc.) on machining precision, a serial of fundamental experiments on elastic material were carried out and optimal process parameters of micro-ECM for elastic material were achieved. After fabrication principle and forming rule of micro cylindrical electrodes were analyzed, micro multi-level cylinder electrodes with 10μm in diameter were successfully made by using online electrochemical machining method with micro circular holes in a stainless steel plate. Based on analyzing structures of flexible parts, micro-ECM process plans for micro trapezoid structure and rectangular micro groove were designed. Micro trapezoid structure (upper bottom width 1.305mm, lower bottom width 0.503mm, height 0.403mm) was machined with micro electrochemical milling method. Micro rectangular groove was machined with micro-ECM via rough machining and finishing machining. A micro cylindrical electrode with 80μm in diameter was used as rough milling process to dissolve most material of the part and left a little margin for finishing machining. Then a micro multi-level cylinder electrode with bottom-surface insulation and lOμm in diameter was used to refine the lateral face of rectangular micro groove. A micro multi-level cylinder electrode with lateral-face insulation was used to mill the bottom surface of the micro rectangular groove. Finally, a micro rectangle groove with slot-width 150.6μm, the groove-bottom radius 10.3μm, bottom-margin thickness 10.5μm, was successfully achieved. The machined trapezoidal micro structures and rectangular micro groove can meet the designed requirements.Theoretical analysis and experimental research show that electrochemical micro milling technology is an ideal method for micro structures of elastic material Ni-Fe alloy 3J21. Micro-ECM technology can be used to machine not only micro structures of flexible parts of military accelerometers, but also similar micro structures of elastic material which is difficult to machine. Moreover, it can prompt the development of micro-ECM.