镁合金表面微弧氧化防护处理的研究

Microarc Oxidation Protective Treatment on Magnesium Alloy

采用微弧氧化技术在AZ91D镁合金表面制备防护膜层,利用SEM、XRD等手段研究不同添加剂对微弧氧化膜层形貌和相成分的影响,并对基体和膜层进行了耐蚀性比较。结果表明:在硅酸钠系电解液中制备的微弧氧化膜层主要由MgO、Mg2SiO_4、MgAl_2O_4及Mg组成。添加Na F所制备的膜层综合性能最好。膜层在3.5%NaCl溶液中腐蚀72h后,表面未出现明显的腐蚀坑,说明该膜层可以提高镁合金基体的耐蚀性能。

The protective film was prepared on AZ91 D alloy by microarc oxidation （MAO）. This paper took research of the influence of different additive on morphology and phase composition of the MAO film by SEM and XRD, and also compared the stain resistance of the substrate and the film. Results showed that the MAO film prepared in Na2SiO3 electrolyte was mainly composed of MgO, Mg2SiO4, MgA1204 and Mg. The comprehen-sive properties of the film which took NaF as additive were the best of all. After immersion in 3.5% NaC1 solu-tion for 72h, there was no visible corrosion pit on the surface of the MAO film, indicating that the corrosion re-sistance of the substrate was improved with this film.