镁合金表面Al2O3-MAO 复合涂层的 高温耐蚀性能研究.

The surface of AM60B magnesium alloy was micro-arc oxidized by adding nano-Al2O3 particles to the electrolyte to prepare Al2O3-MAO composite film, and a single MAO film was prepared without adding nano-MAO particles as control. In 3.5% NaCl solution, the electrochemical experiments of open circuit potential, electrochemical impedance spectroscopy and potentio dynamic polarization curves were carried out at different temperatures. The macroscopic morphology of the sample was observed by optical microscope before and after corrosion. The morphology was observed by scanning electron microscope (SEM) before and after corrosion, and the elements on the surface of oxide film were measured by energy spectrum analyzer (EDS) before corrosion. Finally, the composition of the oxide film was measured by X-ray diffractometer (XRD) before and after corrosion. Results show that the Al2O3-MAO composite film is more uniform and the surface micropores are smaller than the MAO film. At the same temperature, the corrosion resistance of Al2O3-MAO composite film is better than that of MAO film, and the corrosion resistance of Al2O3-MAO composite film decreases with the increase of temperature. [ABSTRACT FROM AUTHOR]