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This study aims to elaborate the influence mechanism of magnetic field on the electrochemical machining (ECM) localization, which is characterized by the ECM drilling technique. Two experiment models are constructed based on the effect of magnetic field on the anodic dissolution: Model 1 is based on the 304 SS│FeCl3 system, in which magnetic field suppresses the anodic dissolution, while Model 2 is based on the Cu│NaCl system, in which magnetic field promotes the anodic dissolution. The experimental results show that the magnetic field improves the ECM localization of the 304 SS│FeCl3 system in ECM drilling, while having no beneficial influence on that of the Cu│NaCl system. It is found through experimental result analysis and comparison that the influence of magnetic field on anodic dissolution is of good correspondence with the influence of magnetic field on the ECM localization. To be specific, when the magnetic field suppresses the anodic dissolution, ECM localization is enhanced by the magnetic field; when the magnetic field promotes the anodic dissolution, ECM localization does not benefit from enhancement by the magnetic field. Such conclusion is of positive significance for the extensive application of magnetic field-assisted ECM.

The authors modeled the electrochemical reactions of ECM with magnetic field using COMSOL commercial software. They studied the effect of filed strength and direction on the electrolyte mass transfer rate and the anodic dissolution amount. The mathematical models of the electrolyte rate distribution and the anodic dissolution amount were established. Simulation results indicated that the magnetic field would enhance the mass transfer rate and anodic dissolution amount and that the direction of the field will play a bigger part than the intensity in this connection. Experiments were also conducted to verify the model accuracy. Their experimental results were in good consistency with those of simulations. It is observed that the direction of the magnetic field that has a decisive say in altering the electrochemical machining system and this conclusion will potentially promote the application of magnetic field assisted electrochemical machining. The magnetic field works favorably to electromagnetic anodic dissolution reactions by improving both the mass transport rate and the corrosion rate.