Investigation On The Flow Field Of Cascade Passage In Blisk Electrochemical Machining

The blisk is one of the core parts of new aviation engine, compared with the traditional bladed disk, it has connection structure comprised of tenons, mortises, and the blades and disc are designed as a whole part, which can reduce the number of parts, lighten the weight of components, improved thrust-weight ratio and reliability. However, the blisk blade channel is narrow, and the materials is difficult to cut, increasing the manufacturing difficulty. Electrochemical machining(ECM) is a non-traditional machining technology based on the electrochemical reaction. ECM has many advantages, such as no tool wear, high production efficiency, no limitations of cutting property of metal materials, etc. ECM has become one of the main processing methods in blisk manufacture.Cascade channel machining is an important step in the blade ECM, the machining precision and surface roughness on the blade surface has a direct impact on the later machining. This article mainly aims at the whole leaf disc to carry out research on blade channel flow field uniformity in ECM. The main research contents are as follows:(1) Aiming at the problem of poor areas of liquid in the machining gap, the static and dynamic auxiliary liquid were put forward, and simulated in CFD. The results show that: using rehydration structure, the areas of poor fluid region can be reduced, and dynamic rehydration method is more conducive than static rehydration way to solve the problem of inhomogeneous flow of electrolyte in machining gap.(2) The orthogonal test of dynamic fluid electrochemical machining was carried out. The test results show that: under the dynamic rehydration method machining blade channel, the maximum cathode feed rate increases from 1.5mm/min to 1.8mm/min, improving the efficiency of electrolytic machining of blisk, reducing the allowances of the concave and convex from 1.54 mm, 1.85 mm to 1.47 mm and 1.76 mm respectively, the surface roughness Ra of the convex part, concave part, and hub becoming 1.424μm, 1.959μm, 0.116μm.(3) In order to reduce the allowances of the convex and concave, the cathode rotary feeding was put forward, carrying out the CFD simulation and experimental verification. The results show that: the allowances of the concave and convex reduce to 1.022 mm and 1.637 mm respectively, providing favorable conditions for the follow-up surface of blade ECM.