Effects of Alloying Elements on Characteristics of Anodic Oxidized Coatings in Various Mg-Al-Zn Series Alloys

抄録

Effects of the alloying element on processing of the environmental-friendly anodizing were investigated in various AZ series magnesium alloys. The phosphate solution was used mainly in the current process without the need for the deleterious materials such as heavy metals or fluoride. Also the characteristics of the formed coatings, such as their structure, composition, and corrosion resistance, were investigated. Anodized coatings became dense with increasing aluminum content of the alloy substrate. X-ray diffraction analysis revealed that the anodized coatings changed amorphous structure in the cases of the magnesium substrate containing aluminum concentration from 1 to 9 mass%. The anticorrosion performance of these coatings with an average thickness of 10 μm varied depending on the aluminum content, and it is concluded that the anticorrosion performance improved with increasing aluminum content except for the anodized AZ61 specimen.