AZ91D镁合金在不同电解液体系中的微弧氧化行为

Micro-arc Oxidation Behaviors of AZ91D Magnesium Alloy in Different Electrolytes

在3种不同电解液体系中,对AZ91D镁合金表面分别进行微弧氧化处理而得到氧化物陶瓷膜,采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)对其表面形貌和相组成进行分析,利用划痕仪测试氧化膜与镁合金基底的结合强度,并用电化学工作站分析氧化膜在模拟人体体液中的腐蚀性能.结果表明:在不同电解液体系中所获氧化膜的表面结构和组成不同;随着氧化时间的延长,微弧氧化涂层与基底的结合力先逐渐增加而后趋缓;微弧氧化处理可明显提高AZ91D镁合金的耐腐蚀性能.

Ceramic coatings were produced on AZ91D magnesium （Mg） alloy by micro-arc oxidation （MAO） technique in three different electrolytic solutions and at different oxidation times. The morphology, mierostrueture and composition of oxidation coatings were investigated by scanning electron microscopy （SEM） and X-ray diffraction （XRD）, respectively. Moreover, the bonding strength between ceramic coatings and AZ91D Mg alloy, as well as corrosion properties of coatings prepared in different electrolytic solutions and at different oxidation times were also evaluated with an MFT-4000 tester and a potentiodynamic polarization tester. The experimental results show that the surface morphologies and the compositions of oxidation coatings are different in different electrolyte systems. The corrosion resistance of AZ91D Mg alloy treated with MAO technique increases obviously. Moreover, the bonding strength between ceramic coatings and AZ91D Mg alloy oxidated for 15 min is the biggest among the prepared samples.