Al-Zn-Mg-Cu合金表面Al_(2)O_(3)-MoO_(2)-SiO_(2)微弧氧化复合陶瓷涂层的制备及其耐腐蚀性能  

Preparation and Corrosion Resistance of Al_(2)O_(3)-MoO_(2)-SiO_(2) Micro-Arc Oxidation Composite Ceramic Coatings on Surface of Al-Zn-Mg-Cu alloy

作　　者：曾娣平 刘志义[3] 邹利华[1,2] 吴海江 ZENG Di-ping;LIU Zhi-yi;ZOU Li-hua;WU Hai-jiang(Department of Mechanical and Energy Engineering,Shaoyang University,Shaoyang 422000,China;Laboratory of Hunan Province for Efficient Power System and Intelligent Manufacturing,Shaoyang University,Shaoyang 422000,China;Key Laboratory of Nonferrous Metal Materials Science and Engineering,Ministry of Education)

机构地区：[1]邵阳学院机械与能源工程学院,湖南邵阳422000 [2]邵阳学院高效动力系统智能制造湖南省重点实验室,湖南邵阳422000 [3]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《材料保护》2021年第8期14-20,27,共8页Materials Protection

基　　金：湖南省教育厅科研优秀青年项目(18B421);湖南省教育厅资助科研项目(20K112);国家重点研究发展计划项目(2016YFB0300900)。

摘　　要：为了增强Al-Zn-Mg-Cu合金零件的耐腐蚀性能,通过在硅酸盐微弧氧化(MAO)电解液中增加钼酸根离子的方法,在合金表面制备了Al_(2)O_(3)-MoO_(2)-SiO_(2)复合陶瓷涂层。通过扫描电子显微镜、X射线衍射和电化学方法分析了钼酸钠的浓度对复合陶瓷涂层的形成、结构特征以及耐蚀性的影响。涂层的扫描电子显微镜(SEM)结果显示:经过15 min的MAO处理后,制备的Al_(2)O_(3)-MoO_(2)-SiO_(2)复合陶瓷涂层由约2μm厚的致密内层和约5μm厚的多孔外层组成,涂层表面出现了2种不同的形貌区域。X射线衍射结果表明:Al_(2)O_(3)-MoO_(2)-SiO_(2)复合陶瓷涂层主要由MoO_(2)、γ-Al_(2)O_(3)和3Al_(2)O_(3)-2SiO_(2)组成。电化学试验表明:当电解液中加入3 g/L钼酸盐时,涂层的孔隙率降低了4个数量级,涂层的腐蚀速率降低约100倍,表现出最好的耐腐蚀性能。In order to enhance the corrosion resistance of Al-Zn-Mg-Cu alloy parts,Al_(2)O_(3)-MoO_(2)-SiO_(2) composite ceramic coatings were formed on alloy surface by adding molybdate ions in the silicate micro-arc oxidation(MAO)electrolyte that was used for micro-arc oxidation.The effects of sodium molybdate concentration on the formation mechanism,structure character and corrosion resistance of the composite ceramic coatings were analyzed by scanning electron microscopy,X-ray diffraction(SEM)and electrochemical method,respectively.The SEM results of the coatings showed that after 15 minutes of MAO treatment,the Al_(2)O_(3)-MoO_(2)-SiO_(2) composite ceramic coating consisted of a dense inner layer of about 2μm thick and a porous outer layer of about 5μm,and two different morphologies could be observed in the coating surface.The X-ray diffraction results showed that the phases of Al_(2)O_(3)-MoO_(2)-SiO_(2) composite ceramic coating were mainly composed of MoO_(2),γ-Al_(2)O_(3) and 3 Al_(2)O_(3)-2 SiO_(2).Electrochemical experiments showed that when 3 g/L molybdate was added to the electrolyte,the porosity of the as-prepared coating reduced by 4 orders,and the corrosion rate of the coating reduced by about 100 times,indicating the prepared composite ceramic coating had the best corrosion resistance.

关 键 词：微弧氧化 钼酸盐 复合陶瓷涂层 耐腐蚀性 

分 类 号：TG174.451[金属学及工艺—金属表面处理]