Research On Electrochemical Machining Of Integral Centrifugal Compressor Impeller

Electrochemical machining (ECM) is an anodic dissolution process of workpiece in a flowing electrolyte where the shape of the tool as cathode is copied into the workpiece as anode. Due to the adequate surface quality, high productivity, no electrode loss, no cutting stress, ECM has a tremendous potential development in the manufacturing field. It will be a great significance to research and master the key technique of ECM, to make a further research in the process of ECM and apply it to industry's practical application.Firstly, the feature and application situation of ECM and integral impeller are introduced in this paper, then the modern machining methods of integral impeller are introduced, through comparing these methods with each other, the status of ECM is affirmed in machining the integral impeller.According to the structure features of closed impeller, the paper researches on the technological process and technological equipment, analyzes the influence of the different technological process in machining process, then determines the reasonable one and discusses the structure of tool electrode. On this basis, the paper designs the equipment of ECM of closed impeller. It has two parts, one is equipment body and the other is electrolyte circulating system. The equipment body employs a design of enclosed type to meet the unique equipment of ECM. The electrolyte circulating system adopts a design of double-box drawer type, having high filtering precision and cleaning conveniently. From different sides, the equipment design should meet to the experimental need and be low cost.In the end, the paper discusses the ECM of centrifugal compressor of 3D integral impeller. Compared with the technology above, a completely different technology, Numerical Control Electrochemical Contour Evolution Machining (NC-ECCEM) is used to process the 3D integral impeller, this technology not only has the advantage of traditional ECM, but also has flexibility of Numerical Control Machining (NCM), and ideally suited to the machining of complex shaped components made from high strength and heat resistant alloys. The paper researches into the problems, such as surface modeling of 3D impeller, structure form of tool cathode, feed mode, freedom degrees setting and form of machine tool. This makes a basis for the NC-ECCEM of centrifugal compressor of 3D integral impeller.