Abstract: Electrochemical Machining (ECM) is a non-contact machining process, the final machining accuracy of which is significantly influenced by the feed direction of cathodes. Since the hub surface of the diffuser with oblique blades is distorted, a comprehensive optimization method of cathode feed direction based on genetic algorithm is proposed for electrochemical machining of the blade surface. In this method, the maximum angle and the gap variance between the cathode side and the hub surface are taken as the evaluation indexes of the genetic algorithm. Under the condition that the maximum angle is relatively small, the gap distribution between the cathode side and the hub surface is more uniform, so as to avoid the phenomenon of uneven margin or overcut on the hub surface. To verify the effectiveness of the optimization method, the fixture is designed based on the optimization results, and the electrochemical machining experiment of diffusers is carried out. The results showed that the machining error of blade surface is less than 0.12 mm, and there is no overcut on the hub surface. The electrochemical precision machining of the diffuser is realized.

Key words: electrochemical machining, diffuser, blade surface, feed direction, machining accuracy