What are the generally feasible surface treatment methods for magnesium alloy die castings?
Your question is difficult to answer, the general casting magnesium alloy surface treatment should be divided into surface coating treatment and surface treatment, although the two are related, but in the process and technology, but there is a big difference, its main features are not the same. Therefore, you must specify the purpose and function of your work before you can tell you the actual surface treatment.
1. chromate passivation method, which is the most widely used and the most important method in industry. The so-called chromate passivation solution is metal with chromic acid, chromate or dichromate as a major component of the film on the metal surface to form a compound composed of trivalent chromium and hexavalent chromium and six metal itself, this film has protective passivation metal corrosion inhibition for. The specific passivation process is to dip the magnesium ingot which is intended to be passivated into the passivation solution. At this time, the surface metal is oxidized by the solution, forming metal ions into the solution. Since the solution is acidic, the following reactions occur: 3Mg ten, 2HN03 = 4Mg0, ten H20, ten 2N02. anodic oxidation is a surface treatment method to increase the thickness of base metal oxide film by electrolytic reaction and to improve the film properties. The film has excellent corrosion resistance and abrasion resistance.
You ask is the appearance of the surface treatment of magnesium alloy, magnesium alloy because of the limited potential difference, so the appearance of the surface treatment on magnesium alloy or zinc alloy as Aluminum Alloy appearance easy or style, the general appearance of the 1 surface treatment) surface temperature paint, 2) anodic oxidation treatment, 3) chemical nickel plating, plating surface treatment, 4) 5) 6) electrophoresis surface treatment, surface coating treatment, 7) PVD appearance. As for the surface of phosphoric acid, chromic acid, manganese and other chemical immersion solution or to do what should be included in the sandblasting, surface oxidation treatment, and drawing, engraving and so on processing is additional processing surface appearance of another way. Basically, it looks like aluminum alloy or zinc alloy, but the key point is that the process is different from the technical complexity. So the reason why the general magnesium alloy is more difficult to produce is that it is here.
