Abstract: Based on interaction between electric field and magnetic field, the two sorts of cathodes with embedded mag- netic circuits are designed for enhancing electrochemical mach- ining(ECM) accuracy. The effects of magnetic field on three mass transport processes in liquid of electrical double layer are discussed. A method to integrate inner sealed gradually changed multiple-pole magnetic circuit (GCMPMC) with outside sealed one for ECM device is presented. Experiment results show that cathode pasted around by magnet,where the magnetic field are perpendicular to the direction of electrolyte flow to avoid fagot and cavity, can improve the flow field of electrolyte and workpiece roughness; cathode with magnet embedded insi-de can reduce the scattered corrosion because the reactant teans-ference is speeded up and the cutting convergence is enhanced. For electrolytic trepanning, an inner sealed structure GCMPMC to plant into cathode is designed. For abnormity cavity machining, in order to intensify the magnetic induction intensity of the machining gap, a specific combined magnetic field is designed by embedding the outside sealed GCMPMC around the exterior of cathode and setting the inner sealed GCMPMC to the workpiece exterior.

Key words: Scattered corrosion, Magnetic field, Electrochemical machining (ECM), Mass transport process in liquid