NaVO_3对AZ91D镁合金微弧氧化膜的影响

Effects of NaVO_3 on Micro-arc Oxidation Coatings on AZ91D Magnesium Alloys

对AZ91D镁合金进行了微弧氧化处理,获得了棕黄色的陶瓷氧化膜层,并研究了不同质量溶度的NaVO3对微弧氧化膜颜色、结构和性能的影响。结果表明,微弧氧化膜层的生长速率随着NaVO3质量溶度的增加逐渐增大,耐蚀性呈先增大后减小的趋势,同时膜层颜色也逐渐变深,但是过量NaVO3的加入不利于反应成膜。EPMA分析表明膜层主要含有Mg、Al、V、O和少量P元素,但含P物相在XRD分析中并没有被检测到,应归因于膜层中P元素含量较少和生成的膜层较薄,使得含P物相在膜层中的沉积量较少。

Brown ceramic oxide coatings were prepared on AZ91D magnesium alloys by micro-arc oxidation,and effects of different NaVO3 concentration on the color,microstructure and properties of the coatings were investigated. The results reveal that with increasing in NaVO3 concentration,growth rate of the oxidation coatings is increased,and corrosion resistance of the coating exhibits firstly increase and then decrease,meanwhile,the color of the coatings becomes dark brown gradually. However,excessive NaVO3 concentration is harmful for the micro-oxidation process. EPMA analysis shows that the coating is mainly contained Mg,Al,V,O and little P element,and absence of the phase containing P element can be observed in the XRD,which is attributed to little P content in the coating and thin coatings resulting in the little deposition containing P phase.