管道内壁离子液体镀铝技术的研究

发布时间：2018-02-04 04:40

本文关键词： 管道内壁离子液体镀铝 316L不锈钢管阻氚涂层　出处：《浙江大学》2015年硕士论文　论文类型：学位论文

【摘要】：国际热核聚变实验堆(ITER)计划中,作为核燃料的氚在金属管道中存在渗透流失情况,这一方面造成宝贵的核燃料损失,另一方面导致环境污染。因此需要在管道内表面制备具有阻氚作用的涂层。大量研究表明,Al2O3/Fe-Al;涂层具有自修复能力,是性能优异的阻氚涂层。但如何在细长管道内壁低温制备Al2O3/Fe-Al阻氚涂层,成为ITER计划中最为关键的技术难题之一本文面向该重要的工程应用背景,在本实验室提出的”室温离子液体镀铝十低温热处理”这一阻氚涂层制备方法的基础上,以管道内壁阻氚涂层制备为目标,设计并研制不锈钢管道内壁室温离子液体镀铝装置,研究影响管道内壁镀铝的因素,用金相显微镜(OM)、扫描电子显微镜(SEM)等分析测试手段对试样厚度、形貌进行表征,用划刻试验对镀层结合力进行考察。首先,在分析国内外现有管道内壁电镀设备的基础上,设计并制造了适于管道内壁离子液体镀铝的流镀装置。确定蠕动泵为离子液体在管道中流动提供动力,并定量调整流速。通过流速,计算得出泵流量的最小值为0.077～0.436 L/min;选用内衬为聚四氟乙烯的橡胶软管作为输送离子液体的软管；设计并制作了用于大气环境下保存离子液体的储液容器,以不锈钢双卡套作为连接待镀管道和镀液流动管路的接头。利用该装置,在大气气氛下,实现了水溶液中管道内壁镀镍试验。其次,根据铜质材料前处理简单易镀且颜色与铝镀层对比性强的特点,利用前述管道内壁电沉积设备,对铜管进行管道内壁的离子液体镀铝研究。经过大量试验,发现不锈钢接头会优先于阳极铝丝溶解,难以实现管道内壁离子液体镀铝。并发现对镀液真空前处理,可以改善镀层质量。最后选用玻璃四通作为管道内壁离子液体镀铝装置中的接头,在镀覆电流密度5mA/cm2,镀覆时长为1h,成功地在铜管内壁镀覆上一层平均厚度约为6μm的铝镀层。最后,对316L不锈钢的管道内壁进行了离子液体镀铝。不锈钢基体前处理的研究表明：在10mA/cm2电流密度活化5min,可获得结合良好的铝镀层；镀铝工艺参数研究结果表明：当转速增大至200r/min时,可使镀铝槽压稳定；对于不同直径的铝丝,存在相应的最大镀覆电流密度,且两者之间成线性关系。此外,还通过去除管道端面毛刺等措施,改善了镀层质量。最终在转速200r/min,镀覆电流密度3mA/cm2,镀覆时长3h条件下,成功地在内径11mm,长500mm的不锈钢管道内壁制备出平均厚度约为10μm的铝镀层,镀层厚度均匀,与基体结合良好。
[Abstract]:In the International Thermonuclear Fusion Experimental reactor (ITERR) program, there is a leakage of tritium as nuclear fuel in metal pipelines, which results in valuable nuclear fuel loss. On the other hand, it is necessary to prepare tritium resistant coatings on the inner surface of the pipeline. A large number of studies show that Al _ 2O _ 3 / Fe-Al; The coating has the ability of self-repair and is an excellent tritium resistance coating. However, how to prepare Al2O3/Fe-Al tritium resistance coating at low temperature on the inner wall of slender pipeline. As one of the most critical technical problems in the ITER project, this paper faces the important engineering application background. On the basis of the "room temperature ionic liquid aluminizing + low temperature heat treatment" method proposed by our laboratory, the preparation of tritium resistance coating on the inner wall of pipeline is taken as the target. A room temperature ionic liquid aluminum plating device for stainless steel pipe inner wall was designed and developed. The factors affecting aluminum plating on the inner wall of stainless steel pipe were studied by metallographic microscope. Scanning Electron Microscopy (SEM) and other analytical methods were used to characterize the thickness and morphology of the sample, and the adhesion of the coating was investigated by scratching test. Based on the analysis of the existing internal wall electroplating equipment at home and abroad, a galvanizing device suitable for aluminum plating on the inner wall of pipeline is designed and manufactured. The creeping pump is determined to provide power for the flow of ionic liquid in the pipeline. Through the flow rate, the minimum value of pump flow is 0.077 ~ 0. 436 L / min, and the minimum flow rate is 0. 077 ~ 0. 436 L / min. The rubber hose lined with polytetrafluoroethylene is selected as the hose for transporting ionic liquid. A liquid storage container for the storage of ionic liquids in atmospheric environment is designed and fabricated. The stainless steel double card sleeve is used as the connection between the receiving plating pipe and the liquid flow pipe, and the device is used in the atmosphere. The experiment of nickel plating on the inner wall of the pipe in aqueous solution was realized. Secondly, according to the characteristics of simple and easy plating of copper material and strong contrast between the color and aluminum coating, the electrodeposition equipment of the inner wall of the pipe was used. After a lot of experiments, it is found that the stainless steel joint will take precedence over the anodic aluminum wire to dissolve the copper tube. It is difficult to realize the aluminum plating on the inner wall of the pipe by ionic liquid. It is found that the coating quality can be improved by vacuum pretreatment of the plating bath. Finally, the glass four-way is selected as the joint in the aluminum plating device for the inner wall of the pipe. When the current density is 5 Ma / cm ~ 2 and the coating time is 1 h, an aluminum coating with an average thickness of about 6 渭 m is successfully deposited on the inner wall of the copper tube. Finally, an aluminum coating with an average thickness of about 6 渭 m is deposited on the inner wall of the copper tube. Ionic liquid aluminizing was carried out on the inner wall of 316L stainless steel pipe. The pretreatment of stainless steel substrate showed that aluminum coating with good bonding could be obtained when activated at a current density of 10 Ma / cm 2 for 5 min. The results show that the aluminum bath pressure can be stabilized when the rotational speed is increased to 200r / min. For aluminum wires with different diameters, there is a corresponding maximum plating current density, and there is a linear relationship between the two. In addition, some measures are taken to remove the burr of the end face of the pipe. The coating quality is improved. Finally, the inner diameter of the coating is 11mm under the conditions of the rotational speed 200rmin, the plating current density 3mA / cm 2 and the coating time 3h. Aluminum coating with an average thickness of about 10 渭 m was prepared on the inner wall of stainless steel pipe with a length of 500mm. The thickness of the coating was uniform and the coating bonded well with the substrate.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ153

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