| With good mechanical properties, and lower relative density, aluminum alloys can withstand greater processing pressure, which have a very wide range of applications. Especially its material impact and good corrosion resistance.can meet the requirements of many industries,such as, the automotive industry, the aerospace industry, the construction and decoration industry and other industries.However, with the fast development of our industry, the corrosion resistance of aluminum alloys can not meet the needs of people living in industrial production. In order to improve the corrosion resistance of aluminum alloy, people usually take same protective measures on the aluminum surface. In recent years, the technology of using organic silane for metal surfaces is a major trend in the development of metal surface preparation, which is low pollution, low toxicity, simple process operation and has excellent corrosion resistance. Silane coupling agents can hydrolyze the hydrolyzable silanol groups and become silicone when it combined with inorganic. Simultaneously, organic substances can react with organic functional groups incorporated, because of its particular structural characteristics, it can be well combined with metal. The study found that the silane coupling agent applied to the aluminum alloy surface, enables the aluminum alloy have a better corrosion resistance.The optimum process conditions of silane films were studied when the aluminum alloy was silylated by the BTESPT silane coupling agent. At the same time, taking advantage of adding cerium can modify the silane films on the aluminum surface.The optimum process conditions of the preparation of silane films were confirmed by orthogonal experiment when the aluminum alloy was silylated by the BTESPT silane coupling agent. The corrosion resistance of the silane films of aluminum alloy was tested by the tafel curves of electrochemical methods, when the silane films were in 3.50% Na Cl neutral solution. The dipping time, curing temperature, curing time were researched for their influence of the corrosion resistance of the silane films. Adding the cerium nitrate salt can modify the silane films. And the corrosion resistance test and surface morphologyon the silane films explore the law of forming film and the impact of nature. By using the scanning electron microscopy to observe the surface structure to understand the film formation mechanism of silane films, using X-ray diffraction to determine the material components of each phase.In this article, using the immersion method to prepare the silane films by the BTESPT silane coupling agent on the aluminum surface. Results found that on the process conditions of V(deionized water): V(ethanol): V(BTESPT silane coupling agent)=20:5:1, the hydrolysis temperature at 30 oC, the hydrolysis solution p H=3, the alkaline solution-treated aluminum sample was 90 s,the hydrolysis time was 8h, the silane solution soak time was 6min, the curing temperature was 160 oC, can obtain silane films with compact structure. Silane films can effectively prevent the intrusion of corrosive aluminum alloy matrix, have better corrosion resistance and well protect aluminum to prevent corrosion.Through the tafel test of blank aluminum and aluminum silane films, it can be seen, the formation of silane films makes the corrosion potential of aluminum move in the positive direction, the corrosion current density decrease, indicating that the silane treatment of aluminum alloy can improve the corrosion resistance of aluminum and protect it.On the optimum conditions, the aluminum alloy was silaned by the BTESPT silane coupling agent, and adding Ce(NO3)3 to modify the property of silane films. By the salt spray test and solution immersion test of rare earth modifying and none-rare earth modifying on the aluminum films, we can found that the corrosion resistance of them are different. By the rare earth modifying, silane films can effectively improve the protective properties of aluminum alloy. |
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