典型有机酸性气体对带锈青铜文物材料的腐蚀发展行为研究

发布时间：2018-07-05 09:08

本文选题：带锈青铜 + 有机酸　；参考：《华东理工大学》2017年硕士论文

【摘要】：青铜文物是宝贵的历史财富,是研究人类文化、历史和金属冶炼史等发展的重要参考。然而,在馆藏文物保护环境中,由于装饰材料挥发释放等产生的有机酸性气态污染物给青铜文物带来了巨大的威胁,因此研究典型有机酸性气体对青铜文物的腐蚀行为及规律对实现青铜文物的预防性保护具有重要意义。根据馆藏青铜文物表面锈层特征,本论文利用电化学法制备了3种带锈青铜,比较研究了裸青铜和模拟带锈青铜文物材料在有机酸性气体环境中的腐蚀过程,并结合SEM、XRD和Raman对腐蚀产物的形貌与成分进行了表征;考察了裸青铜和带锈青铜文物材料在不同浓度有机酸性溶液中的电化学腐蚀行为,研究了不同带锈青铜文物材料在有机酸溶液中的腐蚀行为发展,并比较分析了不同带锈青铜材料间的腐蚀差异。暴露加速腐蚀实验结果表明:青铜腐蚀是富铜相优先腐蚀;带锈青铜在有机酸中腐蚀性表现为:甲酸乙酸,且试样腐蚀较为严重。在甲酸气体中,裸青铜和带Cu20锈青铜最终腐蚀产物为氧化亚铜和浅蓝色甲酸铜晶体,而带混合锈青铜在甲酸气氛中,各锈层腐蚀是同时进行的,腐蚀产物有新生成的碱式氯化铜和淡蓝色甲酸铜晶体。在乙酸气体中,裸青铜和带Cu20锈青铜最终腐蚀产物为氧化亚铜和淡蓝色乙酸铜晶体;带混合锈青铜表面存在三种锈层,其各锈层腐蚀是同时进行的,除了比较稳定的碱式氯化铜外,其他的腐蚀产物均为碱式乙酸铜和乙酸铜晶体。而带CuCl锈青铜中的CuCl会与空气中的水分和氧气反应生成绿色粉状锈碱式氯化铜,而酸性环境会加速这个过程。电化学阻抗结果表明:在有机酸溶液中,各带锈青铜的极化电阻Rp均随着溶液浓度增大而减小,说明随有机酸溶液浓度增大腐蚀速率加快,其中在甲酸溶液中的腐蚀速率明显大于乙酸溶液中,可能是因为甲酸在水溶液中比乙酸更容易电离出H+。动电位极化曲线结果表明:在有机酸溶液中,各带锈青铜自腐蚀电流密度Icorr均随着溶液浓度增大而增大,且在甲酸溶液中的Icorr均大于乙酸溶液中,与阻抗结果一致。同时,在100mg/L甲酸溶液中,带CuCl锈青铜Ieorr最大,而在100mg/L乙酸溶液中,带混合锈青铜Icorr最大,而自腐蚀电流密度越大说明腐蚀越严重。
[Abstract]:Bronze relics are valuable historical wealth and important reference for the study of human culture, history and metal smelting history. However, in the preservation environment of cultural relics in the library, the organic acid gaseous pollutants produced by volatilization and release of decorative materials have brought a great threat to the bronze relics. Therefore, it is of great significance to study the corrosion behavior and law of typical organic acid gas on bronze relics. According to the characteristics of rust layer on the surface of bronze relics collected in the library, three kinds of rusted bronze were prepared by electrochemical method, and the corrosion process of bare bronze and simulated rusted bronze in organic acid gas environment was compared and studied. The morphology and composition of the corrosion products were characterized by SEM XRD and Raman spectra, and the electrochemical corrosion behaviors of bare bronze and rusted bronze in different concentrations of organic acid solution were investigated. The corrosion behavior of different rusty bronze relic materials in organic acid solution was studied, and the corrosion differences among different rusted bronze materials were compared and analyzed. The results of accelerated exposure corrosion test show that the corrosion of bronze is the preferred corrosion of copper-rich phase, and the corrosion of rusty bronze in organic acid is formic acid acetic acid, and the corrosion of the sample is more serious. In formic acid gas, the final corrosion products of bare bronze and copper bronze with Cu20 are cuprous oxide and light blue copper formate crystals, and the corrosion of each rust layer is carried out simultaneously in the atmosphere of formic acid. The corrosion products include new basic copper chloride and light blue copper formate crystal. In acetic acid gas, the final corrosion products of bare bronze and copper bronze with Cu20 are cuprous oxide and light blue copper acetate crystals, and there are three kinds of rust layers on the surface of mixed bronze, each of which is corroded at the same time. In addition to the more stable basic copper chloride, the other corrosion products are basic copper acetate and copper acetate crystal. The copper chloride in the bronze with CUCL rust will react with water and oxygen in air to form rust-base copper chloride in green powder, and the acidic environment will accelerate the process. The electrochemical impedance results show that the polarization resistance R _ p of each rusty bronze decreases with the increase of the concentration of organic acid solution, which indicates that the corrosion rate increases with the increase of the concentration of organic acid solution. The corrosion rate in formic acid solution is obviously higher than that in acetic acid solution, which may be due to the fact that formic acid is more likely to ionize H. The results of potentiodynamic polarization curves show that in organic acid solution, the corrosion current density of rust bronze increases with the increase of solution concentration, and the Icorr in formic acid solution is larger than that in acetic acid solution, which is consistent with the impedance results. At the same time, in 100 mg / L formic acid solution, Ieorr of CuCl rusted bronze is the largest, while in 100 mg / L acetic acid solution, Icorr of mixed rust bronze is the largest, and the higher the corrosion current density is, the more serious the corrosion is.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：K876.41;TG174

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