Characterization and corrosion studies of ceria thin film based on fluorinated AZ91D magnesium alloy

The CeO2 thin film was prepared via sol–gel method on fluorinated AZ91D magnesium alloy surfaces. The surface morphology, composition and the corrosion resistance of the film were investigated in details using scanning electron microscope, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy as well as potentiodynamic polarization tests. It was found that small amount of MgO and MgF2 were encapsulated in CeO2 thin film. The electrochemical measurement results demonstrated that the CeO2 thin film on fluorinated AZ91D magnesium alloy could improve the corrosion resistance approximately by two orders of magnitude compared with that of the bare substrate.