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通过电化学沉积方法,在生物降解镁合金表面覆盖含氟羟基磷灰石(FHA)涂层和缺钙羟基磷灰石(CDHA)涂层。采用X射线衍射、傅立叶变换红外光谱、透射电子显微镜、扫描电子显微镜和能量色散X射线光谱研究涂层特性。结果表明:涂覆纳米FHA涂层的样品具有垂直于样品表面的纳米针状结构,比涂覆CDHA涂层样品的结构更致密和更均匀。纳米FHA涂层比纳米CDHA涂层具有更小的晶粒尺寸,分别为65 nm和95 nm。然而,CDHA涂层比FHA涂层更厚,厚度分别为19μm和15μm。通过极化、浸泡和析氢实验研究的腐蚀行为表明:纳米FHA涂层和纳米CDHA涂层显著降低腐蚀速率并引起钝化。纳米FHA和纳米CDHA涂层可以加速骨状磷灰石层的形成,相比未覆盖的镁合金可以显著减少溶出速率。纳米FHA涂层能对镁合金提供有效的防护并具有更高的腐蚀性能。因此,覆盖纳米FHA涂层的镁合金在整形外科领域具有良好的应用前景。
Fluorohydroxyapatite (FHA) coatings and calcium-deficient hydroxyapatite (CDHA) coatings were coated on the surface of biodegradable magnesium alloys by electrochemical deposition. The coating properties were studied by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The results show that the nano-FHA coating samples have nano-needle structures perpendicular to the sample surface and are denser and more uniform than those coated with CDHA coating samples. The nano-FHA coating has smaller grain sizes than the nano-CDHA coating, at 65 nm and 95 nm, respectively. However, the CDHA coating is thicker than the FHA coating with thicknesses of 19 μm and 15 μm, respectively. Corrosion behavior through polarization, immersion and hydrogen evolution experiments showed that the nano-FHA coating and nano-CDHA coating significantly reduced the corrosion rate and caused passivation. Nano-FHA and nano-CdHA coating can accelerate the formation of osteoidal apatite layer, which can significantly reduce the dissolution rate compared with uncoated magnesium alloy. Nano FHA coating can provide effective protection of magnesium alloys and have higher corrosion resistance. Therefore, the magnesium alloy covering the nano-FHA coating has good application prospect in the field of plastic surgery.