Synthesis and characterization of thin films on magnesium alloy using a hydrothermal method

• Mg(OH)2 films on the surface of the AZ31 magnesium alloy were synthesized using an alkaline hydrothermal method.
• The results revealed that the films consisted of hexagonal nanosheets mostly aligned with the surface.
• Mg(OH)2 films could play an important role in improving the corrosion resistance as passive films.

Mg(OH)2 films were synthesized on the surface of the AZ31 magnesium alloy using an alkaline hydrothermal method. The structures and compositions of the films grown at different treatment times were investigated. The results revealed that the films consisted of hexagonal nanosheets mostly aligned with the surface. The analysis of the composition and structure indicated that the films were composed of Mg(OH)2 with (001) preferred orientation. The potentiodynamic polarization tests showed that the Mg(OH)2 films could play an important role in improving the corrosion resistance as passive films. The morphology and structure of the films were examined by field emission scanning electron microscopy and transmission electron microscopy. The compositions of the films were investigated using a scanning transmission electron microscopy-energy dispersive spectroscopy. The structure and orientation of the films were determined by X-ray diffraction. Potentiodynamic polarization tests were performed to characterize the corrosion behavior.