Influence of Y2O3/Nd2O3 Particles Additive on the Corrosion Resistance of MAO Coating on AZ91D Magnesium Alloy

Micro-arc oxidation (MAO) coatings with the addition of Y2O3/Nd2O3 particles were formed on AZ91D magnesium alloy. The corrosion behaviors of the coated AZ91D samples were studied by using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and immersion test. Scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) were used to characterize the microstructure and elemental compositions of the coatings. It is found that the micropores and defects of the coating decreases with the addition of Y2O3 particles, resulting in the improved corrosion resistance, while the corrosion resistance of AZ91D magnesium alloy is decreased with the addition of Nd2O3 particles.