6061铝合金表面新型黄色微弧氧化陶瓷层的制备与表征

目的 研究6061铝合金表面新型微弧氧化黄色陶瓷层的制备工艺，并对其微观结构、成分、硬度、耐蚀性能等进行表征。方法 在以Na2SiO3为基础的电解液中加入Na2SnO3进行微弧氧化处理，制备出黄色微弧氧化陶瓷层，并与传统白色、黄色、黑色微弧氧化陶瓷层作对比。采用SEM和EDS分析膜层表面形貌和元素分布，借用XPS对膜层进行成分表征，使用硬度计测试其表面硬度，采用电化学工作站和人造海水腐蚀实验评价陶瓷层的抗腐蚀性能。结果 随着电解液中Na2SnO3浓度的增加，陶瓷层中Sn元素含量增加，Si元素含量减少，陶瓷层黄色饱和度不断增强。黄色含Sn陶瓷层制备过程中，电解液中的SnO32-在高温高压下转化为SnO2，导致陶瓷层硬度达到365HV，高于白色与黑色陶瓷层。在3.5% NaCl溶液中进行电化学测试，黄色含Sn陶瓷层的腐蚀电流密度与腐蚀电位分别为9.34×10-9 A/cm2和-0.34 V，耐蚀性优于白色和黄色含Mn陶瓷层。结论 在电解液中添加Na2SnO3可在铝合金表面生成具有较高硬度和耐蚀性能良好的类似沙漠黄色的陶瓷层，为铝及其合金在多领域的应用奠定了一定的实验基础。

Preparation and Characterization of New Yellow Ceramic Coating by Micro Arc Oxidation on 6061 Aluminum Alloy

The work aims to study the preparation process of new yellow ceramic coating on 6061 aluminum alloy by micro arc oxidation (MAO) and characterize the microstructure, composition, hardness and corrosion resistance of the coating. Na2SnO3 was added into the base Na2SiO3 for the MAO treatment to prepare a new yellow MAO ceramic coating which was compared with the white, yellow or black MAO ceramic coatings. The morphology and element distribution were analyzed by SEM and EDS. The composition of the coatings was characterized by XPS. The surface hardness was tested by hardness tester. The corrosion resistance of the ceramic coatings was evaluated by electrochemical workstation and artificial seawater corrosion tests. With the increase of Na2SnO3 concentration in the electrolyte, the content of Sn element in the yellow ceramic coating increased, the content of Si element decreased, and the yellow degree of the ceramic coatings increased continuously. During the preparation of the Sn-containing yellow ceramic coating, the SnO32- in the electrolyte was converted into SnO2 under high temperature and high pressure, resulting in a hardness (365HV) higher than that of the white and black ceramic coatings. The corrosion current density and corrosion potential of Sn-containing yellow ceramic coating were 9.34×10-9 A/cm2 and -0.34 V, respectively after the electrochemical test in 3.5% NaCl solution. The corrosion resistance was better than that of the white and yellow Mn-containing ceramic coatings. The addition of Na2SnO3 can produce a desert-like yellow ceramic coating with high hardness and corrosion resistance on aluminum alloy, which lays an experimental foundation for the application of aluminum and its alloys in many fields.