【作者】 吕向阳；

【导师】 李念兵；

【作者基本信息】 西南大学 ， 物理化学， 2009， 硕士

【摘要】 铝及其合金材料具有质量轻、导热、导电等优良的物理性能,良好的加工性以及高回收性能等,广泛地应用于交通运输、建筑装饰、航空航天、机械电器等行业,其产量和用途已成为仅次于钢铁的第二大金属材料。铝在自然条件下表面能形成一层氧化膜,但是这层膜非常薄,易破损,因而其抗腐蚀能力很差,导致每年因各种环境造成的腐蚀损失是很惊人的。为了提高铝材料的耐腐蚀性能,使铝材能够更好更有效地应用于各个行业中,国内外研究人员运用了各种方法对其进行有效的缓蚀处理。本文以铝、2024铝合金和6063铝合金为研究对象,应用分子自组装、浸泡吸附、磷化和硅溶胶封闭技术,通过对Tafel极化曲线、电化学阻抗谱及等效电路的分析,研究了不同缓蚀剂对铝、2024铝合金和6063铝合金在3.5%NaCl溶液中的缓蚀行为,并探讨了其缓蚀机理。主要研究工作如下:1.有机硼酸基团对铝缓蚀作用的研究将工业高纯铝在对巯基苯硼酸溶液中首先进行自组装,采用交流阻抗法研究了对巯基苯硼酸对铝在3.5%NaCl溶液中的腐蚀行为。实验表明,随着对巯基苯硼酸浓度的变化和组装时间的不同缓蚀效率有所不同。当对巯基苯硼酸浓度为3.2×10^-3mol/L,组装时间为12h时腐蚀电流最小,缓蚀效率最高,达98%以上。2.三聚氰胺对铝合金2024缓蚀作用的研究三聚氰胺对2024铝合金在3.5%NaCl溶液中的腐蚀具有缓蚀作用,当三聚氰胺的浓度为0.02mol/L,pH=5.48时,其缓蚀作用最佳,缓蚀效率高达97.79%,三聚氰胺属混合型缓蚀剂。3.苯甲酸钠对铝合金6063的缓蚀作用研究采用交流阻抗技术和极化曲线技术研究表明,苯甲酸钠对6063铝合金在3.5%NaCl溶液中腐蚀的抑制作用比较明显,在测试浓度范围内其缓蚀效率随缓蚀剂浓度的增大而增加,苯甲酸钠为0.4mol/L时效果最好,缓蚀率为73.37%。但苯甲酸钠是一种阳极型缓蚀剂,在应用过程中应该很好地把握其添加量。4.硅酸钠封闭后处理对磷化6063铝合金耐蚀性能的影响将磷化后的6063铝合金再用硅酸钠（水玻璃）溶液封闭后处理,以进一步提高磷化膜的耐蚀性能。采用交流阻抗和电化学极化曲线手段研究了硅酸钠封闭后处理对磷化膜层耐蚀性能的影响。结果表明,经硅酸钠封闭处理后的磷化膜层,形成了性能较佳的耐蚀层,且其耐蚀性能与预处理磷化时间有关。当硅酸钠溶液浓度为10g/L,封闭时间为10min,磷化时间为10min时,形成的膜层的耐蚀性能最佳,缓蚀率为97.33%。更多还原

【Abstract】 Aluminium and its alloy material have excellent physical properties such as light quality, thermal conductivity,electrical conductivity and good process ability and high recovery performance and have been widely used in transportation,building decoration,aerospace,mechanical appliances, etc.Its production and use have become second only to the iron and steel metal material.Under natural conditions,aluminium can form a layer of surface oxide film.But this layer of membrane is very thin and is easily damaged.Therefore,its corrosion resistance is very poor,which results in the corrosion loss in various environments very amazing each year.In order to improve the corrosion resistance of aluminium material and make aluminium material being used effectively in various applications,domestic and foreign researchers have used a variety of methods to effectively improve its corrosion resistance.In this paper,pure aluminium and its alloys as anode materials were used as the study objects. and Tafel polarization curves and the equivalent circuit of electrochemical impedance spectroscopy were used to study the inhibition behavior of different corrosion inhibitors in 3.5%NaCl solution.The corrosion-resistant mechanism of different corrosion inhibitors was investigated.The main research works are as follows:1.Study on the corrosion inhibition of organic boric group for aluminiumIndustrial high-pure aluminium was self-assembled in a 4-mercaptophenyl-boronic acid solution,and the AC impedance method was then used to study corrosion behaviors of 4-mercaptophenyl-boronic acid on aluminium in 3.5%NaCl solution.The experimental results showed that the corrosion inhibition efficiency was different with the concentration of the 4-mercaptophenyl-boronic acid and assembly time.When the concentration of 4-mercaptophenyl-boronic acid was 3.2×10^-3 mol/L,and assembly time was 12 h,corrosion current was the smallest and the inhibition efficiency was the highest,up to 98%. 2.Study on the corrosion inhibition of melamine for 2024 aluminium alloyMelamine had corrosion inhibition for the 2024 aluminium alloy in 3.5%NaCl solution.When the concentration of melamine was 0.02 mol/L and pH was 5.48,the corrosion inhibition was the best and the efficiency of corrosion inhibition was as high as 97.79%.Melamine belongs to a mixed type inhibitor.3.Study on the corrosion inhibition of sodium benzoate for 6063 aluminium alloyThe experimental results of AC impedance technology and polarization curves showed that sodium benzoate had obvious inhibition of corrosion on the 6063 aluminium alloy in 3.5%NaCl solution.The efficiency of the corrosion inhibition increased with an increase in concentration of sodium benzoate in a certain concentration range.The corrosion inhibition was the best when the concentration of sodium benzoate was 0.4 mol/L.The corrosion inhibition efficiency was 73.37%. However,sodium benzoate is a corrosion inhibitor of anode type;therefore,the amount of its addition should be controlled carefully in the application process.4.Effect of sodium silicate post-processing on corrosion resistance of phosphated 6063 aluminium alloyThe phosphated 6063 aluminium alloy was post-processed with sodium silicate（water glass） solution to improve the corrosion resistance of phosphate coatings.AC impedance technology and polarization curves were used to study the effect of sodium silicate post-processing on corrosion resistance of phosphated 6063 aluminium alloy.The experimental results showed that the phosphated film treated closely with sodium silicate formed a better inhibition corrosion layer,and the corrosion resistance efficiency was related with pre-treatment phosphated time.When the concentration of sodium silicate solution was 10 g/L,closure time was 10 min and phosphating time was 10 min,the corrosion resistance efficiency of the film was the highest and was 97.33%.更多还原