Phosphating passivation coating technology for magnesium alloy

Magnesium magnesium alloys with low density (density is 1.74 g/cm3), high specific strength, specific stiffness and good thermal conductivity, shock absorption, electromagnetic shielding, processing performance and excellent performance such as being easy to recycle, widely used in automotive, aerospace, communication, computer and building materials industry, magnesium alloy for weight loss, energy conservation and emissions reduction component has a unique advantage, It is an ideal material for automobile lightweight. However, the chemical properties of magnesium alloy are active and the standard electrode potential is very negative (-2.34V). At room temperature, magnesium is easy to oxidize to form loose oxide film. If the surface protection treatment is not proper, severe corrosion will occur in the use process.

The phosphating passivation treatment technology can make the surface of magnesium alloy get uniform and corrosion resistant surface protective film, which can be used as the final protective treatment or as the bottom layer of the coating, and improve the adhesion and corrosion resistance of the coating layer.

Magnesium alloy after the phosphatizing passivation treatment and electrostatic powder or spray painting, neutral salt spray test can reach 500-1000 hours, low equipment investment, easy operation, no chromium, nickel heavy metal and other toxic pollutants, low process cost.