【作者】 刘传海；

【导师】 刘常升；

【作者基本信息】 东北大学 ， 材料学， 2009， 硕士

【摘要】 铝及其合金因为其许多优良的性能,在现代社会的各个领域得到了广泛的应用。为避免或减少铝及其合金的腐蚀,通常采用铬酸盐钝化技术在铝及其合金表面形成铬酸盐钝化膜。但是由于铬酸盐钝化膜中含有六价铬,其毒性大,环境污染严重而且易致癌,世界各国纷纷出台政策法规限制或禁止铬酸盐钝化技术的使用,因此开发用于铝及其合金的无铬钝化技术是非常必要的。在无铬钝化技术的实践应用中,钛锆基的无铬钝化体系表现出了良好的工业应用前景。但是钛锆基钝化膜的耐蚀性和油漆附着力还远不及铬酸盐钝化膜,不能满足许多使用条件下对制备技术和性能的要求。本文以AA6061铝合金为试验基材,在钛锆基钝化技术的基础上,研究了钛锆-有机膦酸盐的复合处理技术。利用有机膦酸的化学特性,加强钛锆钝化膜与油漆间的附着力,从而提高整个涂层体系的耐腐蚀性能。主要采用一步成膜法,即有机膦酸作为添加剂添加到钛锆基处理液中处理铝合金以获得钛锆钝化膜与有机膦酸盐膜相互杂化的复合膜。利用点滴实验和中性盐雾实验(SST)测试了所成膜的耐蚀性能。利用单因素实验和正交实验优化了一步成膜法所成膜的制备工艺。利用扫描电子显微镜(SEM)及附带的能谱分析(EDAX)、原子力显微镜(AFM)分析了复合膜的表面形貌,结果表明,所成膜为连续膜。利用交流阻抗实验、浸泡试验和SST研究了复合膜的涂漆性能。为了与一步成膜法所成复合膜的涂漆性能进行对比,又采用了两步成膜法制备复合膜进行涂漆性能研究。两步成膜法即有机膦酸作为后处理剂,对钛锆钝化膜进行二次有机膦酸封闭处理获得钛锆-有机膦酸盐复合膜。结果表明,钛锆-有机膦酸盐复合膜与油漆间的附着力明显提高,涂漆后的钛锆-有机膦酸盐复合膜能有效抑制涂层的起泡和脱漆,提高涂层的耐蚀性能,与涂漆后的六价铬酸盐膜性能相当。另外,两步成膜法的性能稍优于一步成膜法。更多还原

【Abstract】 The aluminium and aluminium alloy are used widely for their good capability. As it well known, the chromate passivation technique is proverbially used for corrosion resistance of aluminum and aluminum alloy. However, the chromate passivation films contains hexavalent chrome which is a kind of extremely poisonous to environment and carcinogenic to the body, many countries in the world have released some policies or laws to restrict or forbid the usage of chromate passivation technique. For all of this, it is very necessary to empolder chrome-free passivation technique.In the practice choice of chrome-free passivation technique, the titanate and/or zirconate passivation system showed gradually nicer foreground of industrial application, but its corrosion resistance and adhesion to paint are so far from chromate passivation films that it can’t meet needs of thynthesis technique and performance in many usage condition. Using chemistry characteristic of an organophosphonic acid, the titanate/zirconate and organophosphonate composite disposal technique for AA6061 alloy was put forward on the base of optimizing and improving the titanate and zirconate passivation technique in this paper. The adhesion to paint and the corrosion resistance of the whole coatings system were both improved.The one-step method, namely, an organophosphonic acid was added to the titanate/zirconate disposal solution as addition reagent and the titanate/zirconate-organophosphonate hybrid films was obtained on AA6061 aluminum alloy was mainly investigated. The corrosion resistance was explored by the methods of dropping test, neutral salt spray test. The thynthesis technique parameters of films obtained by one-step method was researched by single factor test and orthogonal test. The morphology was investigated by scanning electron microscopy with energy dispersive spectroscopy (SEM/EDAX), atomic force microscopy (AFM) and the result showed that the hybrid film is continuous film.The paint performance of the hybrid films was evaluated by adhesion test, dipping test and neutral salt spray test. The two-step method was studied to contrast the one step method更多还原