Cathodic modification, numerical simulation and experimental investigation on electrochemical machining for the small inner-walled ring groove

Abstract

Some important maglierie conductors. pneumatic valves and hydraulic valves made of corrosion-resistant alloy Crl6Fe (1J116) are often applied IN harsh environments. However. it is very challenging to machine the uiner-vvalled ring grooves thar broadly exist in these workpieces. Electrockemical machining (ECM) is regarded as an ideal manufacturing teclmology to machine this kind of structure without residuai stress, metamorphic layers or microcracks. However. the inner-walled ring grooves niachined with ECM with the typical cylindrical cathode are shaped like a little dnun and are not fiat at the bottoni. In this paper, a working-surface curvature cathodic modification and numerical simulation method is proposed to solve tliis problem. First, the working surface of the cathode is modified mto an inward curved surface and is used in the flow field smiulation model in which the k-e equation is employed. Then. tlie coupling analysis of the flow field and the electric field is carned out with COMSOL Multiphysics. The simulation results show that tlie machimng quahty of the mner-walled ring groove is improved with the modified cathode because the flow field distnbutions and the electric field distributions in the machining gap are more unifonn than before. Finally verification experunents with the modified cathode are conducted. The experimental results show that the machmed inner-walled ring groove is of good quality, and the bottoni of the groove is fiat. The experimental results agree with the simulation results. This study is meamngful to provide a probable solution to miprove the machining quality of the inner-walled structure workpieces without residuai stress, metamorphic layers or microcracks.