Experimental Research On Electrochemical Magnetic Abrasive Finishing

Electrochemical magnetic abrasive finishing is a kind of composite processing technology, which combines electrochemical anodic dissolution with mechanical scraping effect of magnetic abrasive grinding, making the utmost of the characteristics of good surface quality, high efficiency of electrochemical machining and high precision of magnetic abrasive machining. EMAF could machine some materials which is relatively difficulty or impossible for traditional machining methods.Passivation film is a bonding point which combines electrochemical machining with magnetic abrasive grinding, taking fully into account of the different technological characteristics of electrochemical and magnetic force grinding, so a hollow structure with electric poles separated by magnetic pole is proposed. This tool is composed alternatingly of electrodes and magnetic poles. The magnetic abrasive adsorbs on the end of the magnetic poles, and rotating with the tool. The composite structure of the tool makes an alternating effect of electrolytic and mechanical grinding, which not only shave the electrolytic products effectively, and discharge the products quickly with a high speed motion, again and again, finally, we will obtain a workpiece with good quality.A magnetic field model, which is a compound machining of electrochemical magnetic abrasive finishing, is established through the finite element method. The magnetic field distribution in the machining gap, the tool face and workpiece end face are simulated, The results show that magnetic induction in center of the grinding area is stronger, while the center area around is weaker; The electrolytic area also has a small amount of residual magnetic field, but the impact on the effect of compound machining is very weak, however, it has a certain restriction to select magnetic abrasive; In the center of the tool area, because of the weaker magnetic intensity and the smaller linear velocity, electrochemical machining is priority in the center area. And a handcraft measurement has validated the simulation results. Secondly, some processing experiments have been tested, which are the main influence factors in the electrochemical magnetic abrasive finishing, and experimental parameters including machining voltage, frequency, duty ratio, processing time, waveforms and tool rotation speed, etc. Experiment results show that through changing the related experimental parameters of electrochemical and magnetic abrasive, different composite effects could be obtained, and this also suggests the matching relationships of the electrochemical and magnetic abrasive have a great influence to the final machining quality and efficiency. To reach a good combination effect, the state of the electrochemical machining should be under the passivation stage, at the same time, the magnetic abrasive grinding removal efficiency of passivation film should be strengthen. Finally, in order to get a reasonable match among the various parameters, an orthogonal experiment is arranged to get an optimal processing scheme, and the differences about the processing effect between stainless steel and A3steel have been analyzed through the contrast experiments.