The Electrode Design And Experiments In Blisk Electrochemical Machining

Turbine blisk, which combines the blades and the disk, is one of the main components ofaero-engine. The structure of connection of blades and disk, effectively reduces the aviation engineparts quantity, improves the thrust mass ratio and increases the reliability. So the turbine blisk waswidely used in modern aircraft engines. However, the blisk is very difficult to process because ofcomplex blades and the material of high temperature resistance, oxidation resistance, hot corrosionresistant, excellent fatigue and fracture properties. Now, the processing technology of the blisk hasbecome a worldwide problem. ECM is able to machine difficult-to cut materials and to producecomplex shaped parts. ECM has no cutting force, no residual stress, no tool wear, and high efficiency,has become a main method to process the engine blisk.Often the machining of the blisk has two processes, one is the machining of the tunnels and theother is the machining of blisk profile. In the process of finishing machining, how to improve themachining accuracy has become an important problem in the machine of blisk. This paper includesthree aspects as follows.1. Based on the theories of electric field, an electric field simulation model of blisk profileelectrochemical finishing machining was developed to analyze the change of the blisk profile in theprocessing and to calculate the minimum allowance of the blisk tunnel. And the electric fieldsimulation also lay a foundation for the cathode design.2. Calculate the minimum allowance for the specific blisk with the method which has proposed.The minimum allowance of blade profile is1.92mm and2.05mm. Furthermore, experimental researchwas carried out with the specific blisk. It showed that the process had gone into a balanced state andno overcutting occurred. The experimental result is consistent with the simulation results.3. Design the cathode for the specific blisk with the method proposed. Also the experiment wascarried out. The accuracy of blade basin and blade back was improved from0.541mm and0.367mmto0.295mm and0.186mm using the cathode after twice modification which was designed with thecosθ method. The accuracy of blade basin and blade back was improved from0.541mm and0.367mmto0.332mm and0.217mm using the cathode which was designed with the method proposed.