A composite anodizing film containing superfine Al2O3 particles on AZ31 magnesium alloy

摘要

Anodized coatings with and without superfine Al2O3 particles have been prepared on AZ31 magnesium alloy by anodizing in an environmentally friendly alkaline solution. The microstructure and morphology of the coatings were analyzed by X-ray diffraction and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS). The corrosion resistance of the substrate and films were evaluated in 3.5% NaCl solution using potentiodynamic polarization tests. Wear tests were performed to evaluate the wear resistance of the samples. Results indicate that the composite oxide coatings have better corrosion resistance than the films produced in nanoparticles free solutions. The microhardness of composite coating with reinforced Al2O3 nanoparticles is up to 358HV. When rubbed at 10N load for 3 min during sliding against GCr15 at ambient temperature, the wear loss of the film was about 0.04mm3, which is about one-tenth of that of the samples without added particles. The composite anodizing coatings have good anti-corrosion and anti-wear properties.