| 摘要: |
| 在含有Na2SiO3、NaAlO2、Na2B4O7、NaOH、C3H8O3及C6H5Na3O7的硅铝复合电解液中，采用恒电流方式对AZ91D镁合金进行微弧氧化处理。利用扫描电镜、膜层测厚仪、全浸泡试验和极化曲线等方法研究了陶瓷膜层的形貌特征、厚度以及耐蚀性能。结果表明，随着Na2SiO3、NaAlO2、Na2B4O7、NaOH、C3H8O3及C6H5Na3O7含量的增加，微弧氧化陶瓷膜层的耐蚀性基本均呈现出先提高后降低的变化趋势；经正交试验优化后，当电解液中Na2SiO3、NaAlO2、Na2B4O7、NaOH、C3H8O3及C6H5Na3O7的含量分别为15 g/L、9 g/L、2 g/L、3 g/L、5 mL/L及7 g/L时，膜层耐蚀性最好。经过微弧氧化处理后试样的腐蚀电流密度较镁合金基体降低了近2个多数量级，自腐蚀电位提高了近73 mV，镁合金的耐蚀性能得到了显著提高。 |
| 关键词: AZ91D镁合金 微弧氧化 电解液 耐蚀性 |
| DOI： |
| 分类号: |
| 基金项目:江苏高校优势学科建设工程资助项目（35061101） |
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| Effects of Constitutes of Electrolyte on the Corrosion Resistance of the Coating Fabricated on AZ91D Magnesium Alloy |
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WANG Shu–yan, XIA Yong–ping, LU Zheng–ping, PENG Zan–yu, HU Rui
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School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang Jiangsu 212003
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| Abstract: |
| Microarc oxidation process was carried out on AZ91D magnesium alloy at a constant current in a dual electrolyte containing Na2SiO3、NaAlO2、Na2B4O7、NaOH、C3H8O3 and C6H5Na3O7. Characteristics of the coating such as morphologies, thickness and corrosion resistance were investigated by scanning electron microscopy, layer thickness meter, immersion test and potentiodynamic polarization test, respectively. The results showed that the corrosion resistance of the coating increased when the concentration of each composition of the electrolyte increased, however it decreased when the concentration increased further. After the test optimized through orthogonal experiment, coating exhibited a better corrosion resistance when the electrolyte consisted of 15g/L Na2SiO3, 9g/L NaAlO2, 2g/L Na2B4O7,3g/L NaOH，5mL/L C3H8O3 and 7g/L C6H5Na3O7. Compared with the magnesium alloy substrate, the corrosion current density of the coated sample decreased more than two orders of magnitude and its corrosion potential approximately increased by 73 mV, indicating an effective protection for the magnesium substrate. |
| Key words: AZ91D magnesium alloy microarc oxidation electrolyte corrosion resistance |
