锆盐体系电解液失效过程研究

发布时间：2018-04-21 10:32

本文选题：镁合金 + 微弧氧化　；参考：《长安大学》2015年硕士论文

【摘要】：本文以AZ91D镁合金为试验基材,锆盐体系电解液为基础溶液进行微弧氧化处理,研究了随着加工过程的进行电解液的衰变规律以及对衰变过程电解液对所加工试样综合性能的影响。然后期通过一定的方法尝试对失效溶液再生,对再生电解液和原电解液的加工性能通过试样的微观形貌进行对比分析,探讨了再生过程的机理及未来的发展可能性。通过试验分析了电解液pH值、电导率、温度变化值对电解液随使用过程失效的变化规律,对所加工试样的耐蚀性、致密度和微观形貌、相组成随失效过程所受影响进行观察,分析。实验发现:失效过程引起电解液的pH值升高,电导率增强,温度变化值降低;试样耐蚀性先下降后上升,致密度先上升后下降,而膜层微观腐蚀形貌,相组成几乎没有发生变化。尝试了已经失效的溶液采用过滤、添加改良剂的办法进行再生,结果表明过滤的方法对老化电解液具有一定作用,但不能有效改善失效电解液;而添加改良剂能够很好地改善失效的电解液,所加工试样与原电解液相比还存在一定差距,有待进一步深入研究。微弧氧化一旦开始进行,电解液中的成分即发生改变(主要是试样的基体成分在反应过程中以杂质形态进入电解液,造成电解液污染),随着加工过程的进行电解液通常也会变得不稳定,伴随的现象首先是溶液内部出现浑浊,随后底部有絮状沉淀析出,起弧电压升高、弧点变大,所加工的试样从表面光洁完整到局部粗糙甚至出现麻点,电解液使用的时间越长(加工工件越多)这种现象越明显。说明微弧氧化过程改变了电解液的性质,同时对所加工试样性能造成影响,而这个过程是无法避免的。本试验在一定量电解液中采用固定电参数研究溶液失效问题,当电解液无法起弧或者试样产生宏观缺陷来确定电解液的失效。
[Abstract]:In this paper, AZ91D magnesium alloy was used as experimental substrate and zirconium salt electrolyte as base solution for micro-arc oxidation treatment. The decay law of electrolyte with the process of processing and the effect of electrolyte on the comprehensive properties of the processed samples were studied. Then through certain methods to try to regenerate the failure solution, the processing performance of the regenerated electrolyte and the original electrolyte were compared and analyzed through the microscopic morphology of the sample, and the mechanism of regeneration process and the possibility of development in the future were discussed. The effect of pH value, conductivity and temperature on the failure of electrolyte was analyzed. The corrosion resistance, density, microstructure and phase composition of the samples were observed. Analysis It was found that the pH value of electrolyte increased, the electrical conductivity increased, the temperature decreased, the corrosion resistance of the sample first decreased and then increased, the density first increased and then decreased, and the micro-corrosion morphology of the film was obtained. The phase composition has hardly changed. The method of filtration and addition of modifier was used to regenerate the failed solution. The results show that the filtration method has certain effect on the aging electrolyte, but it can not effectively improve the invalid electrolyte. The addition of modifier can improve the failure electrolyte, and there is still a certain gap between the processed sample and the original electrolyte, which needs to be further studied. Once the micro-arc oxidation begins, the composition of the electrolyte changes (mainly the matrix of the sample enters the electrolyte in the form of impurities during the reaction. When the electrolyte is contaminated with the electrolyte, it usually becomes unstable with the process of processing. The accompanying phenomenon is the turbidity in the solution, and then there is flocculent precipitation at the bottom, the arc voltage rises and the arc point becomes larger. The sample processed from smooth and clean surface to local roughness or even the occurrence of points, the longer the electrolyte is used (the more workpieces are processed), the more obvious this phenomenon is. The results show that the process of micro-arc oxidation changes the properties of electrolyte and affects the properties of the samples, which is unavoidable. In this experiment, fixed electrical parameters are used to study the solution failure in a certain amount of electrolyte. When the electrolyte can not start arc or the sample produces macroscopic defects, the failure of the electrolyte is determined.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4

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