氟离子浓度对镁合金微弧氧化膜层形成影响规律  

Influence of the Fluoride Ion Concentration on the Micro-arc Oxidation Coating of Magnesium Alloy Substrate

作　　者：李红龙[1] 宁成云[1] 劳永华[1] 谭帼馨[2] 郭远军[1] 廖景文[1] 彭莞婷[1] 郑华德[1] 

机构地区：[1]华南理工大学,广东广州510641 [2]广东工业大学,广东广州510006

出　　处：《稀有金属材料与工程》2013年第8期1707-1710,共4页Rare Metal Materials and Engineering

基　　金：国家重点基础研究发展计划项目(2012CB619100);国家自然科学基金项目(50872035;51072057)

摘　　要：在含有不同氟离子浓度的硅酸钠电解液体系中,采用恒压微弧氧化技术对AZ31镁合金进行表面处理,通过XRD、SEM、EDS等研究镁合金表面微弧氧化膜层形貌和相结构特征,探讨氟离子对膜层形成的影响规律。研究结果表明:随着氟离子浓度的增加,膜层微孔数量逐渐减少,微孔孔径逐渐变大且分布均匀,但氟离子浓度过高时,膜层缺陷增多,出现微裂纹和局部孔径较大的微孔;微弧氧化膜层主要由MgAl2O4和MgSiO3组成,其含量随着氟离子浓度的变化而变化,当氟离子浓度范围为2～4 g/L时微弧氧化膜中MgAl2O4和MgSiO3的含量最高;动电位极化曲线表明微弧氧化膜的耐腐蚀性能也随之呈先增后减的趋势。AZ31B magnesium alloy was treated by micro-arc oxidation （MAO） with a constant voltage in a Na2SiO3 electrolyte system with the different concentrations of fluoride ions. The phase composition and the surface morphology of the micro-arc oxidation film were analyzed by means of XRD, SEM and EDS. Results show that the number of pores is decreased, the pore diameters of coatings are increased and the pores distribute orderly on the coating surface with the increase of the amount of fluoride ions. But when the concentration of fluoride ions is too high, the defects of coatings are increased, including microcracks and some larger-diameter pores The main phase composition of micro-arc oxidation films consists of MgAl2O4 and MgSiO3, whose contents change with the variation of the concentration of fluoride ions, and get the highest when the concentration of fluoride ions is 2-4 g/L. The Zeta potential curves demonstrate the trend of the corrosion resistance of the coating increases at first and then drops

关 键 词：AZ31B镁合金 氟离子浓度 微弧氧化 

分 类 号：TG174.44[金属学及工艺—金属表面处理]