制备时的pH对AZ31镁合金表面铁离子掺杂磷酸氢钙转化膜性能的影响  

Effect of pH during preparation on properties of Fe-doped calcium hydrogen phosphate conversion film on AZ31 magnesium alloy

作　　者：龙启霏 贾素秋[1] LONG Qifei;JIA Suqiu(Changchun University of Technology,Changchun 130000,China)

机构地区：[1]长春工业大学,吉林长春130000

出　　处：《电镀与涂饰》2023年第2期1-6,共6页Electroplating & Finishing

摘　　要：为改善镁合金的耐蚀性,提高医用镁合金的使用寿命,采用液相沉积法,以硝酸钙、硝酸铁及磷酸二氢钠组成的转化液在AZ31镁合金表面制备了一层转化膜,研究了pH对成膜效果和膜层性能的影响。使用扫描电镜、能谱仪和X射线衍射仪探究了膜层的成分和形貌,采用电化学方法考察了试样在Hank’s溶液中的腐蚀行为。结果表明,转化液的pH为6时制备出的铁掺杂磷酸氢钙膜层能有效保护基体。最后探讨了成膜的过程。In order to improve the corrosion resistance of magnesium alloy and extend the service life of medical magnesium alloy, a conversion film was prepared on the surface of AZ31 magnesium alloy by liquid-phase deposition in a solution composed of calcium nitrate, iron nitrate and sodium dihydrogen phosphate. The effect of pH on formation and properties of the conversion film was studied. The composition and morphology of the conversion film were characterized by scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction. The corrosion behavior of the specimens in Hank’s solution was examined by electrochemical methods. The results showed that the iron-doped calcium hydrogen phosphate film prepared at pH 6 provided the best protection for the substrate. The film formation was discussed.

关 键 词：镁合金 磷酸氢钙 转化膜 铁离子 掺杂 耐蚀性 成膜机理 

分 类 号：TG174.4[金属学及工艺—金属表面处理] TG178[金属学及工艺—金属学]