Chromium-free novel protective paints for magnesium alloy, and preparation method thereof

Abstract

The invention relates to a technology of magnesium alloy surface treatment and corrosion protection, and especially relates to chromium-free long-effect protective paints used for enhancing magnesium alloy corrosion resistance. The paints are especially suitable to be used in magnesium alloy corrosion resisting and protection in harsh oceanic climate, and are environmentally friendly. A primer paint and a topcoat provided by the invention are both two-component systems, and are both composed of a color paste (component A) and a curing agent (component B). The two components are stored separately, and are uniformly mixed at a construction site according to certain ratios before painting.

Description

technical field [0001] The invention relates to the surface treatment and anti-corrosion protection technology of magnesium alloys, especially the chrome-free long-term protective coating for enhancing the anti-corrosion ability of magnesium alloys, which is especially suitable for anti-corrosion and protection of magnesium alloys in harsh marine climates, and has environmental protection . Background technique [0002] Magnesium alloy is used as medium density (1.76~1.84g / cm2) in engineering application 3 ) The lowest metal structural material, has the advantages of high specific strength, high specific modulus, electromagnetic shielding, excellent casting, machining performance and easy recycling, etc. It has important application value and broad It is known as "green engineering material in the 21st century". Since magnesium is a metal with strong electronegativity, the standard electrode potential is –2.37V, in humid, CO 2 , SO 2 , Cl – Corrosion is very easy to occ...

AI Technical Summary

Problems solved by technology

Although the sol-gel film-making method has many advantages, there are still some shortcomings: for example, the adhesion between the film and the substrate surface is not good enough, and the film layer is thin. To obtain a thicker film with good adhesion, it is more difficult. Complicated; the volume shrinkage rate is relatively large during the preparation process, and defects are prone to occur; the details of the sol-gel process, such as the reaction mechanism, nucleation mechanism, product quality, etc., need to be fully discussed, and there are no practical conditions at this stage

[0010] Invention patent written by Zhang Jinghai and others, patent number: 200910014834.7 "A Fluorocarbon Topcoat for Anticorrosion of Wind Power Generation Equipment and Its Preparation Method", which discloses the preparation method of fluorocarbon topcoat for wind power generation equipment, and the developed fluorocarbon surface The paint has good weather resistance, but there is no oil resistance index. Generally, the oil resistance of pure fluorocarbon topcoat is not good, so it cannot be used in the environment where there is oil.

[0011] It can be seen that the existing coatings used on the surface of magnesium alloys not only have poor adhesion, but also have defects in corrosion resistance and weather resistance, and most of the coatings contain chromium, which cannot provide long-term effective anti-corrosion protection. Environmental requirements

Images