封闭对铝合金微弧氧化膜在酸性溶液中耐蚀性的影响

发布时间：2018-06-21 07:43

本文选题：铝合金 + 微弧氧化　；参考：《无机材料学报》2015年06期

【摘要】：为了提高7A85铝合金的耐蚀性,采用单极性正脉冲微弧氧化(MAO)技术在其表面制备了陶瓷膜层,并采用稀土铈盐、铬酸盐和SiO2溶胶对MAO膜进行封闭处理。采用扫描电子显微镜(SEM)、X射线衍射仪和电化学工作站研究了封闭处理对膜层表面形貌、结构和在酸性Na Cl溶液中腐蚀行为的影响。实验发现,MAO膜在酸性Na Cl溶液中不能有效地保护铝合金基体。稀土铈盐和铬酸盐封闭处理通过沉积水合氢氧化物封闭孔隙,可以提高MAO膜的耐蚀性。但在酸性溶液中,封孔物质会和H+发生反应而溶解,故经封闭的MAO试样也会发生腐蚀失效。SiO2溶胶封闭处理后MAO膜表面覆盖一层凝胶,使膜层成为完整的致密层,可以保护铝合金基体在酸性Na Cl溶液中免受腐蚀。
[Abstract]:In order to improve the corrosion resistance of 7A85 aluminum alloy, the ceramic coating was prepared on its surface by unipolar positive pulse micro arc oxidation (MAO) technology, and the MAO film was closed by rare earth cerium salt, chromate and SiO2 sol. The sealing treatment of the coating surface was studied by scanning electron microscope (SEM), X ray diffractometer and electrochemical workstation. The effect of morphology, structure and corrosion behavior in acid Na Cl solution. It is found that the MAO film can not effectively protect the aluminum alloy matrix in the acid Na Cl solution. The rare earth cerium salt and chromate sealing treatment can improve the corrosion resistance of the MAO film by sealing the pore of hydrated hydroxide, but in the acid solution, the sealing material will occur with the H+. The reaction and dissolution, so the MAO sample closed will cover a layer of gel MAO film surface corrosion failure of.SiO2 sol sealing treatment, make the film become dense layer complete, Aluminum Alloy can protect the substrate against corrosion in acidic Na Cl solution.
【作者单位】：西北工业大学腐蚀与防护研究所;中航工业第一飞机设计研究院;
【基金】：国家自然科学基金(51171154) 轻合金加工科学与技术国防重点学科实验室开放课题研究基金(gf201401001)~~
【分类号】：TG174.4

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