Design method and experimental study of a cathode tool with an extremely high leveling ratio for electrochemical machining of blisk  

作　　者：Moqi SHEN Jia LIU Jingtao WANG Di ZHU 

机构地区：[1]College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China

出　　处：《Chinese Journal of Aeronautics》2024年第4期593-608,共16页中国航空学报（英文版）

基　　金：sponsored by the Industrial Technology Development Program (Grant No. JCKY2021605B026, and National Natural Science Foundation of China (Grant No. 92160301))。

摘　　要：To obtain final parts with the desired dimensional accuracy and repeatability via electrochemical machining(ECM), the machining process must enter an ECM balanced state. However,for the ECM processing of blisk, a key component of aerospace engines, the surface of the blade blank often has an uneven allowance distribution due to the narrow passage of the cascade. It is difficult to remedy this issue in subsequent processing steps, which is necessary to ensure the dimensional accuracy and repeatability of the final blade profile. To solve this problem, electrolytic machining must be preceded by electrolytic shaping, which requires cathode tools with large leveling ratios to quickly homogenize the blank surface of the blade. In this study, to obtain a cathode tool with an extremely high leveling ratio, a design method based on the variation in the electrode gap in the non-equilibrium electrolytic state is proposed, and a dissolution model based on the nonequilibrium state is established. In this design method, the allowance on the blank to be machined is first divided into many discrete allowances with the normal direction. The initial machining clearance, feed rate, and total machining time are then calculated using classical ECM equilibrium state theory based on the maximum allowance. Meanwhile, the point coordinates of the cathode tool at maximum allowance can be determined. The non-equilibrium model can then be used to calculate the relative coordinate positions corresponding to the remaining discrete allowances. Finally, the entire cathode tool profile is designed. Simulations, fundamental experiments, and blisk unit workpiece experiments were carried out to validate the design approach. In the simulated processing of the plane workpiece, the leveling ratio of the cathode tool designed by the proposed method(0.77)was 83% higher than that of the cathode tool designed using the traditional method. The simulation results were confirmed by processing experiments. In the machining of blisk unit workpieces with compl

关 键 词：Electrochemical machining(ECM) Non-equilibrium machining Large leveling ratios Cathode design Finite element simulation BLISK 

分 类 号：V26[航空宇航科学与技术—航空宇航制造工程]