Based on the study of phosphate to permanganate chemical conversion treatment of magnesium alloy, it is found that the treatment solution with pH 4, K2HPO4 content of 150g/L and KMnO4 content of 40gL can significantly improve the surface corrosion resistance of magnesium alloy. Phosphating treatment is generally used as the bottom layer of coating treatment. A chemical conversion film was prepared on AZ91D magnesium alloy by adding magnesium inhibitor into the system composed of manganese salt and phosphate.

Typical phosphating process: degreasing and acidizing oxidation peeling → pickling (70~80° C, 10min)→ phosphating → pure water washing → dry aging.

Organic protective coating is usually used as the last protective measure with other anti-corrosion means, widely used. The key of this technology is to improve the adhesion and corrosion resistance of the coating. The surface roughness of the bottom layer and the properties of the coating material determine the adhesion and corrosion resistance. The protective effect of organic coating is to act as a barrier layer between the metal body and the environmental medium, preventing the transfer of water, ions, 02 and charge to the body and preventing the formation of corrosive circuits. Organic coating protection technology has the advantages of variety and color diversity, wide adaptability, low cost and simple process.

The above is the correct way to improve the corrosion resistance of magnesium alloys. If you have more methods or better suggestions, please feel free to contact us.