Zn-ZrO_2复合镀层的结构与耐蚀性

Structures and Corrosion Resistance of Zn-ZrO_2 Composite Coating

采用扫描电镜和X射线衍射仪对Zn-ZrO2复合镀层的表面形貌和结构进行分析,并采用浸泡腐蚀试验、电化学阻抗测试法,对纯锌镀层和Zn-ZrO2复合镀层的耐蚀性能进行了比较。结果表明,加分散剂的Zn-ZrO2复合镀层中ZrO2颗粒粒径约为1μm;在复合镀层XRD谱图中出现了Zr特征峰。从浸泡试验结果得出,在弱酸性、碱性及中性环境中Zn-ZrO2复合镀层耐蚀性优于纯锌镀层,其主要原因是镀层中存在适量的ZrO2颗粒。

The surface morphology and structures of Zn-ZrO2 composite coating was observed by scan electron microscopy and X-ray diffraction. The corrosion resistance of pure zinc coating and Zn-ZrO2 composite coating was comparatively investigated through corrosion immersion test and EIS. The results showed that the diameter of ZrO2 grains was about 1 μm in the Zn-ZrO2 composite coating with dispersant. Zr characteristic absorption band appeared in the XRD pattern of Zn-ZrO2 composite coating. Zn-ZrO2 composite coating exhibited better corrosion resistance than pure Zn coating in weak acid, alkaline and neutral solutions. The existence of ZrO2 grains in the composite coating was the main reason for the better corrosion resistance of composite coating than that of pure zinc coating.