中文摘要：

以氢氧化钙和磷酸二氢钙为前驱物,在AZ31镁合金表面通过溶胶凝胶法制备了羟基磷灰石涂层。利用X射线粉末衍射仪（XRD）、扫描电子显微镜（SEM）对涂层的物相组成、表面形貌、截面进行了分析表征,利用电化学工作站测试了该涂层在生理盐水中的动电位极化曲线和电化学阻抗谱,并对涂层在Hank’s模拟体液中的析氢量和浸泡腐蚀形貌进行了表征。结果表明,溶胶凝胶法制备的羟基磷灰石涂层纯度较高,结晶性良好,涂层厚度在8μm左右;动电位极化曲线结果显示,该涂层的腐蚀电流密度为1.486 4×10-2 mA/cm2,与空白镁合金的腐蚀电流密度相比降低了5倍左右。析氢试验及其浸泡腐蚀形貌进一步说明羟基磷灰石涂层能有效地保护镁合金基体。

英文摘要：

In this paper, Ca（OH）2and Ca（H2PO4）2 · H2O were used as raw materials to pre- pare a hydroxyapatite coating on the surface of AZ31 magnesium alloy using a sol-gel technique. Phase analysis, surface morphology study, and cross-section and microstructure characterization of the hydroxyapatite coating were conducted. Potentiodynamic polarization curves and electro- chemical impedance spectra were obtainod using electrochemical workstation. Hydrogen evolution rates and corrosion morphologies of the coating immersed in Hank＇s solution were also presen- ted. The results indicate that the thickness of hydroxyapatite coating is approximately 8 μm and the corrosion current density of hydroxyapatite coating is 1. 486 4 ×10^-2 mA/cm2 , which is 5 times lower than that of bare AZ31 magnesium alloy. Hydrogen evolution tests and immersion corrosion morphologies further illustrate that hydroxyapatite coating can slow down the rate of biodegradation of AZ31 magnesium alloy effectively.