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利用微弧氧化处理技术,在以硅酸钠为主体的电解液中加入一定量的石墨烯添加剂,在纯镁表面制备出致密均匀、耐蚀性能好的陶瓷层。用SEM分析了纯镁微弧氧化陶瓷层的表面和截面形貌,用XRD分析了陶瓷层的相结构。利用CHI600E电化学腐蚀工作站,在3.5%Na Cl溶液中测试了微弧氧化陶瓷层的腐蚀性能。结果表明,处理1200 s后的微弧氧化陶瓷层厚度约为30μm,且显微硬度达到486.73 HV。微弧氧化陶瓷层主要由Mg、MgO、SiO_2和SiC相组成。电化学腐蚀测试表明在电解液中添加石墨烯后,有效改善了微弧氧化陶瓷层的耐蚀性能,腐蚀速率仅为2.01×10~(-4)mm/a,较原始试样2.1363 mm/a减小4个数量级,石墨烯加入电解液后制备的微弧氧化陶瓷层的耐蚀性能显著改善。
By using micro-arc oxidation technology, a certain amount of graphene additive is added to the electrolyte mainly composed of sodium silicate to prepare a dense and uniform corrosion resistant ceramic layer on the pure magnesium surface. The surface and cross-sectional morphology of the pure MA micro-arc oxidation ceramic layer were analyzed by SEM. The phase structure of the ceramic layer was analyzed by XRD. Using CHI600E electrochemical corrosion workstation, the corrosion performance of MAO ceramic coatings was tested in 3.5% NaCl solution. The results show that the micro-arc oxidation ceramic coating has a thickness of about 30μm after 1200 s and the microhardness reaches 486.73 HV. Micro-arc oxidation ceramic layer is mainly composed of Mg, MgO, SiO 2 and SiC phase. Electrochemical corrosion tests showed that the addition of graphene to the electrolyte can effectively improve the corrosion resistance of the MAO coating with the corrosion rate of 2.01 × 10 -4 mm / a, which is lower than that of the original sample of 2.1363 mm / a decrease of 4 orders of magnitude, the corrosion resistance of MAO coatings prepared by adding graphene to the electrolyte is significantly improved.