Improving machining accuracy of electrochemical machining blade by optimization of cathode feeding directions

Abstract

Electrochemical machining (ECM) is well-established in certain areas, such as the aerospace, defence, and medical industries for machining complex parts. ECM is an effective way to produce compression blades. However, with advances in the development of aero engines, the accuracy of blades becomes higher and their shapes have also become more complex. Thus, considerable attention has been devoted to improving the machining accuracy of blades by ECM. In blades machined by ECM, the angle between the cathode feeding directions and the normal of the anode profile greatly affects the accuracy of the ECM process, and it is determined by the angle combination of the anode installation and the cathodes feeding direction. It is very important to determine the best angle combinations that could minimise the angle between the cathode feeding directions and the normal of the anode profile. The present paper focuses on the optimization method of the angle combinations of the cathode feeding directions and anode installation. A theoretical model describing the optimization method of the cathode feeding directions and position of the anode was developed, and the experimental investigations were conducted in order to evaluate the rationality of the optimization method. The results show that with the optimized combination of the cathode feeding directions and position of the anode, the maximum angle between the cathodes feeding directions and the normal of the anode profile is minimised and the inter-electrode gap between the cathode and anode is more uniform. Thus, the machining accuracy could be clearly improved and the maximum errors of the convex part and concave part were only 0.054 and 0.047 mm, respectively.