Magnesium alloy surface treatment method

Abstract

The invention discloses a magnesium alloy surface treatment method which comprises three stages including a pretreatment stage, a spraying stage and an after-spraying treatment stage. By adoption of a compound spraying method, an anti-corrosion and anti-abrasion coating layer which is high in bonding strength, high in compactness and small in environment pollution is formed on the magnesium alloy surface; the surface treatment method is simple and feasible and is low in cost.

Description

technical field [0001] The invention belongs to the thermal spraying field of material processing engineering, and relates to a magnesium alloy surface treatment method for forming a corrosion-resistant and corrosion-resistant coating on the surface of the magnesium alloy by using a thermal spraying method. Background technique [0002] China is the country with the most abundant magnesium resources in the world. The proven reserves of magnesite account for about 1 / 4 of the world, and it has the inherent basic conditions for the development of the magnesium industry. In addition, China is not only a big country in motorcycle production, consumption and export, It is also a big automobile production and consumption country, and the market application prospect of magnesium and magnesium alloy products is broad; the biggest disadvantage of ordinary magnesium alloy is that it is easy to oxidize and burn during melting and forming, which makes the smelting of magnesium alloy very ...

AI Technical Summary

Problems solved by technology

[0003] At present, the surface treatment methods such as coating, anodic oxidation treatment, micro-arc oxidation treatment, chemical conversion treatment, etc. can improve its oxidation resistance and corrosion resistance. However, there are also limitations that cannot be ignored. Although micro-arc oxidation treatment and chemical conversion treatment can improve its oxidation resistance and corrosion resistance, there are also limitations that cannot be ignored; the research on the corrosion resistance of chemical conversion coatings shows that The chemical conversion coating can only slow down the corrosion rate but cannot effectively prevent corrosion, and the anodic oxidation film is porous, so the coating must be sealed and the process is complicated; the micro-arc oxidation also has a serious defect of generating harmful ions, which does not meet the current requirements. Requirements for environmental protection development; it is usually very difficult to electroplate or chemically plate metal on the surface of magnesium alloys, because magnesium alloys are very active, and the surface quickly forms an oxide film to prevent the formation of metal-metal bonds between the coating metal and the substrate; magnesium is an alkaline earth metal , the replacement reaction with other metal ions in solution is very violent

And because magnesium alloys have a low ignition point and are easy to burn, thermal spraying and hot dipping are generally not used. In summary, the surface treatment methods for magnesium alloys currently used have some shortcomings such as complex processes, high costs, and environmental pollution. Greatly increased the cost of use of magnesium alloys; therefore, developing a magnesium alloy surface treatment method that can overcome the above defects has become a technical problem to be solved urgently by those skilled in the art