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

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

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To obtain final parts with the desired dimensional accuracy and repeatability via electro-chemical 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 dimen-sional 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 non-equilibrium 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 clear-ance,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 work-piece 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 complex curved surfaces,the leveling ratios of the convex and concave parts of the blade machined using the proposed cathode tool respectively reached 0.75 and 0.54,which are 75%and 38%higher than those obtained using the traditional method.This new cathode design method and machining technology can significantly improve the surface allowance distribution of blank before electrolytic finishing.It is helpful for finishing machine to enter electrolytic equilibrium state.Finally,the final blade profile accuracy can be guaranteed and repeated errors can be reduced.

Electrochemical machining(ECM)Non-equilibrium machiningLarge leveling ratiosCathode designFinite element simulationBlisk

Moqi SHEN、Jia LIU、Jingtao WANG、Di ZHU

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College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China

Industrial Technology Development Program国家自然科学基金

JCKY2021605B02692160301

2024

中国航空学报(英文版)
中国航空学会

中国航空学报(英文版)

CSTPCDEI
影响因子:0.847
ISSN:1000-9361
年,卷(期):2024.37(4)
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