Impact of magnetic field on corrosion performance of Al–Mg alloy with different electrode potential phases

Abstract

We investigated the influence of magnetic field on the corrosion performance of Al-3.0 Mg-xRE/Fe alloys using microstructure observation, immersion test, electrochemical measurement, and pH and conductivity tests. The effects of both magnetic field and the change in the solution properties on the corrosion performance of Al-3.0 Mg alloy with different phases were discussed. The results indicated that the application of magnetic field in 3.5 wt% NaCl solution can reduce the pitting sensibility and corrosion rate of Al-3.0 Mg-xRE/Fe alloys. However, magnetic field treatment could also lead to the increase in the pH and conductivity of NaCl solution. The application of magnetic field can cause changes in the solution properties, thus changing the corrosion rate of Al-3.0 Mg alloy with different phases. The effect of magnetic field on the corrosion performance of Al-3.0 Mg-xRE/Fe alloys was due to the appearance of paramagnetic gradient force/magnetohydrodynamic flow and the change of solution properties during the corrosion process. Magnetic field had different effects on the corrosion behavior of Al-3.0 Mg alloys with different electrode potential phases. The appearance of paramagnetic gradient force/magnetohydrodynamic flow and the change of solution properties under magnetic field both reduced the corrosion rate of Al-3.0 Mg-xRE alloys (with anode phases). However, for Al-3.0 Mg xFe alloys (with cathode phases), the paramagnetic gradient force/magnetohydrodynamic flow induced by magnetic field reduced the corrosion rate of the alloys, while the change of solution properties under MFT accelerated the corrosion process.