Gao Dandan, Dou Jinhe, Hu Cheng, Yu Huijun, Chen Chuanzhong
Shenzhen Research Institute of Shandong University Shenzhen 518057 Guangdong P. R. China
Key Laboratory of High-efficiency and Clean Mechanical Manufacture (Shandong University), Ministry of Education, School of Mechanical Engineering, Shandong University Ji'nan 250061 Shandong P. R. China
RSC Adv. 2018 Jan 22;8(7):3846-3857. doi: 10.1039/c7ra12497j. eCollection 2018 Jan 16.
Microarc oxidized calcium phosphate (CaP) ceramic coatings were fabricated on Mg-2Sr alloy from silicate electrolytes with different concentration gradient poly(ethylene glycol) (PEG). The microstructure, phase and degradability of the ceramic coatings were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and simulation body fluid (SBF) immersion tests respectively. An electrochemical workstation was used to investigate the electrochemical corrosion properties of the coatings. It is found that microstructure, thickness, adhesive strength and degradation rate are influenced by PEG incorporation through adjusting the electrolyte activity and then altering the coating growth mechanism. Similar thicknesses (39.0-42.2 μm) are observed in PEG-containing coatings while their PEG-free counterparts possess the maximum value (51.5 μm). The weight gain in the first two days of SBF immersion suggests that a new layer containing CaP apatites is generated. Results show that ceramic coatings prepared in the electrolyte containing 8 g L PEG exhibits the highest corrosion resistance and lowest degradation rate.
采用不同浓度梯度聚乙二醇（PEG）的硅酸盐电解液在Mg-2Sr合金上制备了微弧氧化磷酸钙（CaP）陶瓷涂层。分别通过扫描电子显微镜（SEM）、X射线衍射（XRD）和模拟体液（SBF）浸泡试验对陶瓷涂层的微观结构、相组成和降解性能进行了评估。使用电化学工作站研究了涂层的电化学腐蚀性能。研究发现，通过调节电解液活性进而改变涂层生长机制，PEG的加入会影响涂层的微观结构、厚度、结合强度和降解速率。含PEG涂层的厚度相似（39.0 - 42.2μm），而不含PEG的涂层厚度最大（51.5μm）。SBF浸泡前两天的重量增加表明生成了一层含CaP磷灰石的新层。结果表明，在含8 g/L PEG的电解液中制备的陶瓷涂层具有最高的耐腐蚀性和最低的降解速率。
