Design Of Electrochemical Machining Tooling And Cathode For Aeroengine Blade Surface

Titanium alloy turbine blades are the core components of aircraft engines,and their complex structure,bending blades and high hardness of materials lead to traditional blade processing methods that cannot meet the requirements of high-precision and high-performance processing of aviation components.Electrochemical machining is a method that uses the principle of electrochemical anodic dissolution to remove metal materials,which has the advantages of no cutting stress and is not affected by the hardness of the processed material.In this paper,the design of cathode and tooling fixture for electrochemical machining of the blade type of a small aero engine is studied,and verified by process tests,and the main research contents are as follows:(1)The initial structure of the cathode of titanium alloy turbine blade is designed.The digital modeling of the standard aeroengine turbine blade is carried out based on UG NX platform.The initial design of the cathode profile is completed by the equal gap method combined with the blade body profile,and the initial design of the cathode structure is completed in combination with the flow of electrolyte.(2)The fixture of electrolytic machining of titanium alloy turbine blade surface is designed.Firstly,the overall design of the fixture is completed according to the existing equipment;Secondly,the advantages and disadvantages of electrolyte flow mode are analyzed and the electrolyte flow mode is selected;The fixture is subdivided into diversion parts,positioning fixtures,cavities and sealing parts,and the design is completed and the flow channel post-treatment is carried out.(3)The characteristics of flow field,electric field and magnetic field in the flow channel during electrochemical machining of titanium alloy blade profile are analyzed,the multi physical field coupling model is established,the flow field,electromagnetic field and electric field magnetic field flow field coupling numerical simulation are carried out,the distribution laws of electrolyte flow rate,workpiece surface pressure,electrolyte current density,magnetic field strength and potential in machining gap are obtained,and the flow field,electromagnetic field and multi physical field coupling numerical simulation are compared respectively.The results show that the stability of flow field in machining gap is positively related to the uniformity of current density distribution on anode surface.Finally,the cathode profile is corrected by the current density distribution on the blade profile.(4)Through the polarization experiment,the electrolyte formula is selected,the optimized cathode and its fixture are processed,and the electrochemical machining test of titanium alloy turbine blade surface is carried out.The roughness of the obtained profile is detected and measured by three-dimensional coordinates.The roughness of the blade basin is Ra0.479?m.The surface roughness of blade back profile is Ra0.484?m.The measured three-dimensional point coordinates are compared with the standard blade body point coordinates to obtain the error.The blade basin contour error is ± 0.15 mm and the blade back contour error is ± 0.15 mm.The correctness of the cathode and tooling fixture design method in this paper is verified.The test showed that the multi physical field coupling model established in this paper can accurately simulate the ECM process,provide a theoretical basis for parameter optimization and cathode and fixture design,and is of great significance to shorten the ECM design cycle and improve the machining quality.