离子液体中纳米晶铝的电沉积制备及其防腐蚀性能研究

发布时间：2018-04-09 03:18

  本文选题：离子液体　切入点：电沉积　出处：《浙江大学》2015年硕士论文

【摘要】：铝具有光泽性、良好的延展性、导电性、导热性,且表面易生成致密的氧化膜,具有很好的耐蚀性。但传统的涂镀铝方法能耗大,污染环境等,而且金属铝不可能通过在水溶液中电沉积的方法得到,而只能在质子惰性的非水体系中获得,离子液体具有范围较广的电化学窗口,为铝的沉积提供了必要条件。 本文用摩尔比为3:2的AlCl3-EMIC离子液体为电镀液,主要研究内容为：①测试添加不同量的添加剂2-氯烟酰氯后离子液体电沉积过程中的循环伏安曲线,分析其电化学特性；②测试添加不同量添加剂2-氯烟酰氯后离子液体开路电位和沉积电位下的阻抗值变化,分析添加剂对离子液体的影响；③探究脉冲电流电镀条件对镀层的影响；④采用SEM、XRD、EDS.动电位极化曲线、阻抗曲线等测试手段对镀层形貌、纯度、物理性质、耐腐蚀性能进行测试；⑤探究具有相似结构的添加剂对电镀效果影响；⑥通过热处理增加铝镀层表面的氧化膜厚度,提高其防腐蚀性能。 结果表明：随着添加剂量的增加,其循环伏安曲线中阴极沉积区沉积电流逐渐变小,从原来的17mA/cm2降低为15mA/cm2,电流效率随着添加剂的增加而逐渐降低,铝的起始沉积电位也会负移0.1V,而且添加添加剂的离子液体其开路电位和沉积电位下其阻抗值也要高于未添加的离子液体；通过SEM对镀层形貌进行观察发现当添加剂的量达到40-50mg时,能成功的得到粒径为15nm左右的纳米铝镀层,相较于微米级铝镀层,纳米铝镀层外观光亮光滑,镀层更加致密,但是当离子液体中添加剂的量过大时,铝镀层的表面会产生微米级的突起,铝镀层发黄发暗,会有明显的粗糙感；脉冲电流电镀的得到的铝镀层要好于直流电电镀。在质量比为3.5%NaCl溶液中进行动电位极化曲线、阻抗和浸泡的测试发现纳米级铝镀层其耐腐蚀性能要远远好于常规微米级铝镀层,其腐蚀电流降低了一个多数量级；通过热处理即在250℃马弗炉里加热12h后确实能够提高铝镀层的耐腐蚀性能。
[Abstract]:Aluminum has luster, good ductility, electrical conductivity, thermal conductivity, and the surface is easy to form a dense oxide film, with good corrosion resistance.However, the traditional methods of aluminum plating are characterized by high energy consumption and environmental pollution, and aluminum can not be obtained by electrodeposition in aqueous solution, but can only be obtained in non-aqueous proton inert systems. Ionic liquids have a wide range of electrochemical windows.It provides the necessary conditions for the deposition of aluminum.In this paper, AlCl3-EMIC ionic liquids with a molar ratio of 3:2 were used as electroplating solution. The main content of this study was to test the cyclic voltammetry curves of ionic liquids after the addition of different amounts of additive 2-chloronicotinyl chloride, and to analyze their electrochemical characteristics.(2) the impedance changes of ionic liquids under open circuit potential and deposition potential were tested after adding different amounts of additive 2-chlorniacyl chloride. The influence of additives on ionic liquids was analyzed. The influence of pulse current electroplating conditions on coating was investigated. 4 SEMXRDX EDS4 was used.Potentiodynamic polarization curve and impedance curve were used to test the morphology, purity, physical properties and corrosion resistance of the coating. 5. The effect of additives with similar structure on the electroplating effect was investigated.6 the thickness of oxide film on the surface of aluminum coating is increased by heat treatment, and its corrosion resistance is improved.The results show that the deposition current in the cathodic deposition area in the cyclic voltammetry curve decreases from the original 17mA/cm2 to 15 Ma / cm 2, and the current efficiency decreases with the increase of the additive content.The initial deposition potential of aluminum also shifted negatively to 0.1V, and the open-circuit potential and impedance of the ionic liquid added with additives were also higher than those of the unadded ionic liquid.The morphology of the coating was observed by SEM. It was found that when the amount of additive reached 40-50mg, the nanometer aluminum coating with the diameter of 15nm could be obtained successfully. Compared with the micrometer aluminum coating, the nano-aluminum coating had a bright and smooth appearance, and the coating was more compact.However, when the amount of additives in ionic liquids is too large, the surface of aluminum coating will produce micron protrusions, and the coating will have a yellowish and dark color, and it will have an obvious sense of roughness, and the aluminum coating obtained by pulse current electroplating is better than that obtained by direct current electroplating.The potentiodynamic polarization curve in 3.5%NaCl solution with mass ratio was carried out. The results of impedance and immersion test showed that the corrosion resistance of nanometer aluminum coating was much better than that of conventional micrometer aluminum coating, and the corrosion current decreased by one order of magnitude.The corrosion resistance of aluminum coating can be improved by heat treatment in 250 鈩，

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