Studyon Silane Passivation Solution And Propertiesof Metal Surface

Every year a third of the total metal output was corroded in the whole world, therefore how to prevent metal corrosion has become a major scientific research project. Even though traditional skills such as Chromate passivation, phosphate conversion can solve the problem of Metal corrosion, they pollute the environment and pose a threat to human health. With the green chemical industry clean production put forward, developing a new type of green environmental metal surface treatment technology is imminent. Silane which has a unique chemical structure can form a protective layer on the metal surface. The protective layer can prevent corrosion. In consequence, silanization metal surface treatment technology is considered to be the most ideal alternative. The silanepassivation solution for surface treatment which is made up of organic silicon resin and polyurethane resin mixed with some metal ionshas been applied in a variety ofmetal and metal alloy corrosion resistance.Through consulting a large number ofliterature on metal surface anti-corrosion treatment technology, this paper elaborates the present situation and prospect ofthe silanization metal surface treatment technology, the existing processing technology, equipment technology and engineering technology. In addition, this paper analyzes the condition in actual production application, and summarizes the differences between the application of silicon alkylation for metal surface treatment and the traditional metal surface protection technology, finding out the advantages and disadvantages of the silane processing technology and pointing out the future research direction that needs to be improved of this treatment technology.The study shows that after the silane treatment, the Me –O- Si covalent bond can be formed between the metal surface and the organic silane resin.Through the hydrolysis of-OH in organic siloxane, first and then the intermolecular and intramolecular condensation and polycondensation reaction, and finally the dehydration condensation ofthe-OHon the surface of the metal and the-OH in the passivation solution, the formation of the Me-O-Si covalent bond is acquired, which achieves the goal of the metal surface passivation. Silicon alkylation treatment technology has incomparable superiority to other surface treatment technology, itcauses no pollution, has a good corrosion resistance ability, combines with coating strongly,produces no slag in the process, is feasible in the room temperature and compatible with the original coating process etc.Besides, it also owns the merits of environmental protection,energy saving, low emissions, low use cost and higher application value. But the silane film is very thin(0.2um to 0.3um). It is because of these reasons that make it will not be able to prevent metal corrosion for a long time. What’s more, the silane thin film do not have the ability of self-healing,so the metal surface silicon alkylation treatment technology which is low-cost and environmental friendly, and has the self-healing ability and stronger corrosion resistance of the metal surface needs further development. Meanwhile, the stability of siloxane hydrolysis into silicon resin and the theories on how to prevent the failure of silane passivation solution still need further in-depth exploration.Metal surface silicon alkylation treatment technology as a new type of environmentally friendly pretreatment technology has been used widely in the world. The processing technology of the United States, Germany, Japan and other developed countries is comparatively mature. In China, Shandong university, Nanjing university, Nankai university and some research institutions also began to investigate the mechanism, influencing factors and the preparation method of the silane treatment technologyin the early part of this century,and obtained certain research results. Currently the silicon alkylation treatment technology is mainly used in aluminum, magnesium, iron, zinc, and other areas of the metals and their alloys. For example, it has been widely used in the washing machine, air conditioner, auto parts and other industries. As in the washing machine, air conditioner, auto parts and other industries have been widely used. However, the application of it in the area of engineering materials such as carbon steel still needs further research.This thesis mainly concentrates on the following two points: 1, with silicone, fluorine picks acid, Si Sols, polyurethane resin and metal nitrate as raw materials, the silane passivation solution applied in the cold-rolled sheet is prepared,then through changing the type and content of each component in the passive solution,the anti-corrosion and the stable performance of the passivation solution are improved. At the same time, after the infrared spectrum analysis, ultraviolet spectrum analysis, thermogravimetric analysis, scanning electron microscopy(sem) analysis, electrochemical analysis, salt water invasion bubble experiment, copper sulfate, pitting and film hardness and adhesion tests, theresults show thatthe passive solution is composed of silicon resin,Si Sols,polyurethane resin, fluorine picks acid and zinc nitrate(accounting for 3% of the total), when p H is adjusted to 4.0, the formation of hybrid membrane has the best anti-corrosion effect, hybrid film hardness reaches to 4 H, the film adhesion on the manufacture is level 0, thepassivation solution has a good stability and demonstates no precipitation phenomenon at the room temperature in 360 days.2, fluorine picks acid, silicone,Si Sols,polyurethane resin and metal nitrate as raw material, the silane passivation solution applied in the aluminum sheet is prepared, then through changing the type and content of each component in the passive solution,the anti-corrosion and the stable performance of the passivation solution are improved. At the same time, after the infrared spectrum analysis, ultraviolet spectrum analysis,thermogravimetric analysis, scanning electron microscopy(sem) analysis, electrochemical analysis, energy spectrum analysis, film hardness and adhesion tests, the results show that the passive solution is composed of silicone, polyurethane resin, fluorine picks acid and nitric acid manganese(accounting for 12% of the total), when p H is adjusted to 3.3, the formation of hybrid membrane has the best anti-corrosion effect, hybrid film hardness of 4 H, film on aluminum plate adhesion strongest reached a level 0, thepassivation solution has a good stability and demonstates no precipitation phenomenon at the room temperature in 360 days.