Numerical Solution for Cathode Design of Aero-engine Blades in Electrochemical Machining

Abstract

Electrochemical machining (ECM) is one of the most vital produce methods of aero-engine blades due to the high efficiency and surface quality, stress free and no tool loss. However, the main difficulties encountered with ECM are tool cathode design problem. To solve the problem, an accurate model and numerical approach based on the potential distribution in inter-electrode gap is proposed in this paper. This numerical approach can determinate the electric field in inter-electrode gap and find a cathode (tool) shape which will satisfy the Laplace equation for potential distribution and all other boundary conditions to achieve the desired blade shape. In addition, the influence of passive electrolyte on the cathode design in ECM process is also investigated. The proposed approach does not require iterative redesign process and has excellent convergence and computing accuracy. In order to verify the machining accuracy of the designed cathode, the experiments have been conducted using an industrial scale electrochemical machining system. The experimental results demonstrate that the machined blade samples have high surface quality and dimensional accuracy which proves the proposed approach for cathode design of aero-engine blades in ECM is applicable and valuable