Tu Xiaohua, Miao Chengping, Zhang Yang, Xu Yaling, Li Jiayou
College of Biological and Chemical Engineering, Jiaxing University, Jiaxing 314001, China.
Materials (Basel). 2018 Sep 5;11(9):1618. doi: 10.3390/ma11091618.
Plasma electrolytic oxidation (PEO) coatings were produced on AZ31B magnesium alloys in alkaline electrolytes with the addition of various concentrations of Al₂O₃ sols. Effects of Al₂O₃ sol concentrations on the microstructure, phase composition, corrosion resistance and hardness of PEO coatings were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness testing and potentiodynamic polarization measurements, respectively. It was revealed that the Al₂O₃ sol mostly participated in the formation of the ceramic coating and transferred into the MgAl₂O₄ phase. With the increase of the Al₂O₃ sol concentration in the range of 0⁻6 vol%, the coating performance in terms of the microstructure, diffraction peak intensity of the MgAl₂O₄ phase, corrosion resistance and microhardness was improved. Further increase of Al₂O₃ sol addition did not generate better results. This indicated that 6 vol% might be the proper Al₂O₃ sol concentration for the formation of PEO coatings.
在添加了不同浓度Al₂O₃溶胶的碱性电解液中，在AZ31B镁合金上制备了等离子体电解氧化（PEO）涂层。分别通过扫描电子显微镜（SEM）、X射线衍射（XRD）、显微硬度测试和动电位极化测量，评估了Al₂O₃溶胶浓度对PEO涂层微观结构、相组成、耐腐蚀性和硬度的影响。结果表明，Al₂O₃溶胶主要参与陶瓷涂层的形成并转化为MgAl₂O₄相。在0⁻6 vol%范围内，随着Al₂O₃溶胶浓度的增加，涂层在微观结构、MgAl₂O₄相衍射峰强度、耐腐蚀性和显微硬度方面的性能得到改善。进一步增加Al₂O₃溶胶的添加量并没有产生更好的效果。这表明6 vol%可能是形成PEO涂层合适的Al₂O₃溶胶浓度。
