Hard anodizing is usually also known as hard oxidation, the main purpose of hard anodizing treatment of aluminum alloy is to improve the various properties of aluminum and aluminum alloys, including corrosion resistance, wear resistance, weather resistance, insulation and adsorption. It is suitable for both deformed aluminum alloy and may also be used for die-cast aluminum alloy parts. Hard anodizing is a kind of anodizing that has higher requirements for the wear resistance of the part oxide film, which can generally be divided into:

1.Sulfuric acid hard anodizing method

2.Oxalic acid hard anodizing method

3. Mixed acid type hard anodizing.