Properties of AZ91D magnesium alloy Anodized in Oxalic and Sulfuric Acids and its corrosion resistance in 3.5% NaCl solution

In the article, the AZ91D magnesium alloy was anodized to dramatically enhance its chemical and physical properties. The thickness, hardness, roughness, surface morphology and corrosion resistance of anodized magnesium alloy was investigated. The hardness of AZ91D magnesium alloy is extremely increased after anodizing treatment. The anodized magnesium prepared in oxalic acid solution is the thinnest and has the smallest roughness while the anodized magnesium obtained in sulfuric acid solution is the thickest and possesses the largest surface roughness. The surface morphology of anodized magnesium alloy is porous structure. It was discovered that the anodized magnesium prepared in oxalic and sulfuric acid solutions had a homogeneous porous surface with the maximum hardness and charge transfer resistance, resulting in the best corrosion resistance.