Magnesium alloy soaked in silver

The following are some common magnesium alloy immersion treatments and related introductions:

Chemical conversion coating treatment immersion

Process Introduction: Chemical conversion coating is a method of forming a film layer directly on the surface of magnesium alloy through chemical reaction between ions in the film-forming solution and metal. When the magnesium alloy is immersed in a specific solution, the components in the solution will react with the surface of the magnesium alloy to form a conversion film, which can improve the corrosion resistance and decorative properties of the alloy.

Solution composition: Taking the environmentally friendly molybdate conversion film as an example, at room temperature, the magnesium alloy product is immersed in a molybdate film-forming solution with a pH of 1.5-3.5 for 5-30 minutes, and a beautiful, corrosion-resistant, and light-absorbing black film layer can be formed on the surface. However, if a silvery-white appearance is to be obtained, other solutions may be used, such as solutions containing rare earth elements (such as cerium, lanthanum, praseodymium, etc.), which can form a conversion film with certain protective properties and lighter color under appropriate pH conditions.

Effect: The prepared conversion film has uniform color and good bonding with the substrate, which can improve the corrosion resistance and paint film adhesion of magnesium alloy. At the same time, it can meet certain special appearance requirements, such as in some application scenarios such as electronic equipment casings that require a silver-white appearance.

Phosphate treatment immersion

Process introduction: Phosphating treatment is the process of forming a phosphate conversion film on the surface of magnesium alloy. Usually, the magnesium alloy is immersed in a solution containing phosphate, zinc, calcium, manganese and other components, and reacts under certain pH value and temperature conditions.

Solution composition: For example, in the zinc-calcium-manganese magnesium alloy phosphating process, the solution contains 15-20g/L NaH₂PO₄, 10-15g/L additives, and a pH value of 3.5-4.5. After soaking at room temperature for about 10 minutes, a phosphating film with a fine appearance and gray or flesh-colored can be obtained. If a silver-white effect is to be obtained, the formula may need to be adjusted, such as changing the content of certain ingredients or adding special additives.

Effect: The phosphating film can fill the micro defects of the substrate, improve the bonding strength between the magnesium alloy surface and the coating, reduce shrinkage and blistering after coating, thereby improving the coating quality and the first-time pass rate, and also can improve the corrosion resistance of the magnesium alloy to a certain extent.