ABSTRACT

A solution of Al(NO₃)₃.9H₂O and NaOH was used to perform Mg-Al LDH plugging treatment on the LA103Z magnesium-lithium alloy micro-arc oxidation ceramic layer. The effect of treatment temperature on the micro-arc oxidation ceramic layer structure and corrosion resistance was studied. The formation mechanism of Mg-Al LDH film and corrosion mechanism of the film layer were discussed. The results show that the sealing essence of Mg-Al LDH is that the Mg²⁺ obtained by dissolving the MgO component of the MAO film layer is combined with OH^– in the hydrothermal solution to form a layered Mg(OH)₂, the formation of LDH tends to be inside the pores. In the lower temperature range, the temperature increase is conducive to the increase and thickening of the LDH layer and the film layer is dense and corrosion resistant. In the higher temperature range, the increase in temperature is conducive to the increase in the size of the LDH layer. The layer is loose and coarse, and the corrosion resistance is reduced. The composite film is the densest at 90^oC, and its insulation and corrosion resistance are better than the composite film obtained at other temperatures, the MAO film and the substrate.

摘要

使用Al（NO ₃）₃ .9H ₂ O和NaOH的溶液在LA103Z镁锂合金微弧氧化陶瓷层上进行Mg-Al LDH堵塞处理。研究了处理温度对微弧氧化陶瓷层结构和耐蚀性的影响。讨论了Mg-Al LDH膜的形成机理和膜层的腐蚀机理。结果表明，镁铝LDH的密封实质是，所述Mg ²⁺由MAO薄膜层的MgO成分溶解获得与OH结合^-在水热溶液，以形成分层的Mg（OH）₂，LDH的形成倾向于在孔内。在较低的温度范围内，温度升高有利于LDH层的增加和增厚，并且膜层致密且耐腐蚀。在较高的温度范围内，温度的升高有利于LDH层尺寸的增加。该层是疏松和粗糙的，并且耐腐蚀性降低。复合膜在90 ^o C时最致密，其绝缘性和耐腐蚀性优于在其他温度下获得的复合膜，MAO膜和基材。