Technologies Research On Tilted Blisk Profile Electrochemical Machining

Blisk, which is one of the essential components of aero-engine, is very difficult to process becauseof its complicated structure, twisted blade profile, difficult-to-machine material and some otherfeatures. Electrochemical machining (ECM) is a non-traditional machining technology based on theelectrochemical reaction. Because of its significant advantages, such as no tool wear, low productioncost, high efficiency, and no restriction from mechanical properties of metal materials, ECM hasbecome one of the main methods to manufacture the blisk.This paper, which focuses on precision blisk profile ECM, includes the following several aspects.(1) A new method, namely tilted blisk profile ECM, was presented. The optimal tilted angle of aspecific blisk was identified as44.5°based on the principle to minimize the evaluation parameter,which was the maximum angle between workpiece surface normal directions and feeding direction.The angle range between workpiece surface normal directions and the feeding direction reduced from33.565°~68.145°to0°~24.598°. As the machining gap between the cathode and anode was reducedand became more uniform, the machining accuracy was enhanced.(2) As the tilted blisk ECM thin-sheet cathode deformed easily in the electrolyte, C-shapedreinforced structure was designed. By optimizing, the optimal thickness of the C-shaped reinforcedstructure was acquired: the convex cathode’s was4mm, and the concave cathode’s was6mm. One wayfluid-structure interaction method was used to carry out the comparative analysis of the cathodedeformation. The result showed that, by using the C-shaped reinforced structure, the convex cathodedeformation reduced from0.0523mm to0.0037mm, and the concave cathode deformation reducedfrom0.0614mm to0.0074mm.(3) The contrast experiments of the blisk tilted angle before and after optimization were carried out.The experiments used the same electrolyte flow mode and processing parameters. The results revealedthat the machining accuracy of the blisk placed with the optimal tilted angle was enhanced.(4) The experiment on the tilted blisk fan section blank was carried out. The blisk was placed withthe optimal tilted angle and the optimal cathode was used. The detection results showed that themachining accuracy of the convex and the concave were0.23mm and0.12mm respectively, and therepeat accuracy was about0.05mm. It verified the feasibility of the tilted blisk ECM method.