铸造铝合金微弧氧化形膜工艺及其氧化膜耐磨特性的研究

发布时间：2018-09-07 14:05

【摘要】：随着现代工业及科学技术的发展,铝合金材料用量越来越多,但其耐磨、耐冲刷烧蚀、耐蚀性能较差,大大限制了其应用领域,亟待一种表面处理技术来解决。微弧氧化作为一种新兴的表面处理技术解决了上述应用难题,并在生产实践中取得了很好的效果。目前关于铝合金的微弧氧化研究一般多见于硬铝系列合金,而铸造铝合金由于含硅量较高,且硅元素有碍于微弧氧化,因此关于铸造铝合金的微弧氧化研究相对较少。为此,本文采用双极性非对称脉冲电源,对铸造铝合金微弧氧化过程中主要影响因素及膜层性能进行了较为系统地研究,将膜层厚度、硬质层的硬度,硬质层的比例作为主要指标,来研究氧化时间、电源参数、电解液浓度等对膜层的影响,通过实验了解铸造铝合金微弧氧化的基本规律。首先,对微弧氧化技术进行了简介,并对微弧氧化技术在国内外发展及应用情况进行了综述。接着,对微弧氧化膜层的生长机制进行了研究分析,分析了产生微弧氧化电击穿的原因。然后,利用涡流测厚仪、X射线衍射仪、扫描电镜等检测仪器,以ZL101为材料,在弱碱性电解液中进行大量微弧氧化试验。对不同氧化时间、电解液参数、电参数等参数下制备的氧化膜的厚度、硬质层的硬度、硬质层的比例进行了研究,得出了参数对氧化膜的影响规律;最后,进行了陶瓷膜摩擦磨损量和摩擦系数与摩擦时间的实验;微弧氧化、镀硬铬和热喷涂三种金属改性处理试样的磨损特性之对比实验;摩擦系数随载荷的变化情况的实验,探讨了某些工艺参数与摩擦磨损特性的关系。结果表明,微弧氧化膜层制备工艺参数的变化直接影响氧化膜的性能,通过对工艺参数的控制和优化,可以实现对微弧氧化膜层生长过程的预测、控制与优化,从而制备与基体结合强度高、耐磨性能优异的微弧氧化膜层。
[Abstract]:With the development of modern industry and science and technology, more and more aluminum alloy materials are used, but its wear resistance, erosion resistance and corrosion resistance are poor, which greatly limits its application field, and needs a surface treatment technology to solve the problem. As a new technology of surface treatment, micro-arc oxidation has solved the problems mentioned above, and has achieved good results in production practice. At present, the research on micro-arc oxidation of aluminum alloy is usually found in hard aluminum alloy series, but the micro-arc oxidation research of cast aluminum alloy is relatively rare because of the high silicon content and the fact that silicon element is hindering the micro-arc oxidation. In this paper, the main influencing factors and properties of casting aluminum alloy during micro-arc oxidation are studied systematically by using bipolar asymmetric pulse power supply. The thickness of the film and the hardness of the hard layer are studied. The effects of oxidation time, power supply parameters and electrolyte concentration on the film layer were studied by using the ratio of hard layer as the main index, and the basic law of micro-arc oxidation of cast aluminum alloy was studied through experiments. Firstly, the microarc oxidation technology is briefly introduced, and its development and application at home and abroad are reviewed. Then, the growth mechanism of the microarc oxide film was analyzed, and the reason of the breakdown was analyzed. Then, a large number of micro-arc oxidation tests were carried out in weak alkaline electrolyte by means of eddy-current thickness meter, X-ray diffractometer and scanning electron microscope, using ZL101 as the material. The thickness of oxide film, the hardness of hard layer and the proportion of hard layer were studied under different oxidation time, electrolyte parameters and electrical parameters. Experiments on friction and wear amount, friction coefficient and friction time of ceramic film, comparison of wear characteristics of three kinds of metal modified samples, such as micro-arc oxidation, hard chromium plating and thermal spraying, were carried out. The relationship between some technological parameters and friction and wear characteristics is discussed. The results show that the change of the process parameters directly affects the performance of the oxide film. Through the control and optimization of the process parameters, the prediction, control and optimization of the growth process of the micro-arc oxide film can be realized. Thus, the micro-arc oxide film with high bonding strength and excellent wear resistance was prepared.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4

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