优秀毕业设计精品]铝合金无铬导电氧化膜的研究.doc

铝合金无铬导电氧化膜的研究
摘要:铝合金表面导电氧化是铝合金表面化学氧化处理的重要方法之一,广泛用于计算机、黑匣子、雷达、无线电导航、电子通讯设备、电台机箱等,具有工艺操作简单、成本低廉、膜层致密、导电性好、防电磁干扰等优点。传统的导电氧化工艺主要基于铬酸盐体系,但铬酸盐有毒,污染环境。因此,开展导电性好、耐蚀性高的环保型无铬导电氧化工艺对于推动表面工程行业清洁生产技术水平提高具有重要作用。
因此,在综述铝合金表面处理及导电氧化技术发展现状基础上,通过正交试验优化钼酸盐、锰酸盐二个导电氧化体系溶液配方与工艺参数,评价其膜层的理化性质,分析成膜机理,得到了以下结果:
钼酸盐与锰酸盐导电氧化膜,均呈金黄色,外观平整、均匀、光滑、致密、含C、Al、O、Mn四种元素,钼、锆含量较低。而且,两种膜的耐蚀性相差不大,锰酸盐氧化膜的膜电阻比钼酸盐氧化膜小很多。因此,锰酸盐化学氧化膜的性能更加优良。
关键词:铝合金;导电膜;无铬氧化
Study on chromium-free conductive
oxidizing processes for aluminum alloy
ABSTRACT:As an important methods for chemical oxidation treatment of aluminum alloy, conductive oxidation with the simple process, low cost, compact film, good conductivity and ic interference is widely used puters, black boxes, radar, radio navigation, munication equipment, radio chassis, and so on. Traditional conductive oxidation process is mainly based on chromate system. However, chromate is toxic and seriously pollutes the environment. In order to obtain the conversion coating with good conductivity, high corrosion resistance and environment friendly, it is crucial to carry out the study of non-chrome conversion coatings.
In this work, we optimized the condition of solution formula and technology parameters, characterized the morphology and position. In addition, position, corrosion resistance of oxide film, membrane resistance, morphology and the mechanism of chemical oxidation were also investigated. It could be safely concluded that as follows:
Molybdate and manganese acid salt conductive oxidation films including four elements (C, Al, O and Mn) were golden yellow, appearance of smooth, uniform, smooth and dense. Contents of molybdenum and zirconium were low. The corrosion resistance of two films slightly varied. The film resistance of Manganese acid salt Oxidation film was much less than Molybdate Oxidation film. So, the performance of manganese acid salt chemical oxidation film was more excellent.
Keywords:Aluminum alloys; Conductive film;Cr-free oxidation
引言
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