阳极氧化铝表面MgAl-LDH的原位构筑及改性研究

Preparation and Modification of MgAl-LDH Film on Anodic Aluminum Oxide

摘要:

为了提高铝合金的耐蚀性能，本文采用阳极氧化法在铝表面制备多孔阳极氧化膜，并以阳极氧化膜为骨架，用原位生长法在其表面构筑具有层状双金属结构的镁铝水滑石（MgAl-LDH）。首次利用缓蚀剂二苄基二硫代氨基甲酸锌(ZBEC)对制备的MgAl-LDH膜层进行改性,通过SEM、EDS、XPS、FT-IR研究了改性MgAl-LDH膜层的形貌成分,通过电化学阻抗谱(EIS)技术研究了ZBEC浓度、改性温度、改性时间对改性膜层耐腐蚀性能的影响。结果表明,水滑石膜层呈垂直于基体表面的片状交错结构,ZBEC分子可以成功的和MgAl-LDH膜层进行结合。当ZBEC改性溶液的浓度为0.03 mol/L、温度45℃、时间15 min时,改性前后膜层的EIS低频模值由7.94×103Ω.cm2增加到1.995×10_⁶ （10的6次方）Ω.cm2,说明ZBEC改性提高了MgAl-LDH膜层的耐蚀性能。

Abstract:

In order to improve the corrosion resistance of aluminum alloy, a porous anodizing film was prepared on the surface of aluminum by anodizing method, and a magnesium-aluminum hydrotalcite (MgAl-LDH) with layered bimetallic structure was constructed on the surface by the in situ growth method using the anodic oxide film as the skeleton. For the first time, zinc dibenzyl dithiocarbamate (ZBEC) was used to modify the prepared MgAl-LDH film layer, and the morphological composition of the modified MgAl-LDH film layer was studied by SEM, EDS, XPS and ft-IR, and the effects of ZBEC concentration, modification temperature and modification time on the corrosion resistance of the modified film were studied by electrochemical impedance spectroscopy (EIS).The results show that the hydrotalcite film layer is a flaky staggered structure perpendicular to the surface of the matrix, the ZBEC molecule can successfully bind to the MgAl-LDH film layer, and the modified film layer has a good binding force. When the concentration of ZBEC modified solution was 0.03 mol/L, the temperature was 45°C, and the time was 15 min, the EIS low-frequency modulus value of the modified film layer increased from about 7.94×100000 Ω?cm2 to 1.995×1000000 Ω?cm2, indicating that the ZBEC modification improved the corrosion resistance of the MgAl-LDH film layer.