AZ91D镁合金表面羟基磷灰石涂层的构建及其腐蚀行为

Preparation and Corrosion Resistance of Hydroxyapatite Coating on AZ91D Magnesium Alloy

采用水热法,以乙二胺四乙酸二钠(EDTA)作为耦合剂,在AZ91D镁合金表面制备羟基磷灰石(HA)涂层。利用场发射扫描电子显微镜(FESEM)、X射线衍射仪(XRD)和红外光谱(FT-IR)等检测方式,分析了镁合金表面HA涂层的结构和相组成。结果表明在10g·L-1 EDTA,pH=5.5,反应温度为95℃,反应时间为8h时,涂层的致密性最好,呈放射性的花状结构,主要成分为HA相。涂层的厚度约为10μm,与基体结合较好。电化学测试及仿生溶液浸泡试验结果证明:HA涂层对镁合金基体有较好的保护作用,显著提高了基体在生理溶液中的耐腐蚀性能。

In this paper,hydroxyapatite（HA）coating was prepared on the surface of AZ91 D magnesium alloy by a hydrothermal method through using ethylenediamine tetraacetic acid disodium salt（EDTA）as a coupling agent.The morphology and phase composition of the coating were characterized by field-emission scanning electron microscopy（FESEM）,X-ray diffraction（XRD）,and Fourier transform infrared spectroscopy（FT-IR）.It was demonstrated that when the reaction lasts for 8hunder the temperature condition of 95℃ with EDTA 10g·L-1,pH =5.5,the compactness of the coating was meet the requirements.The as-prepared coating with the composition of HA has a radioactive flower-like structure.Moreover,the coating with the thickness of 10μm bonds well with the substrate.Electrochemical tests and immersion test in simulated body fluid（SBF）revealed that the corrosion resistance of the substrate was significantly improved after being coated with HA coating.