Formation and Characterization of Hydroxyapatite Coating Prepared by Pulsed Electrochemical Deposition

采用交流脉冲沉积法在AZ91D镁合金表面合成了羟基磷灰石涂层。考察了交流脉冲电压、沉积时间及电解液添加剂等电化学沉积参数对羟基磷灰石涂层的形貌、微观结构、元素组成及电化学性能的影响。结果表明,当脉冲电压为110 V时,纳米级别的羟基磷灰石涂层表面更为均匀,孔隙度更小,且其XRD的特征衍射峰更为突出。当电解液中添加了NaN O3和H2O2后,羟基磷灰石颗粒和涂层表面形貌均得到优化;同时,极化曲线和交流阻抗测试结果表明该涂层在模拟体液中的耐蚀性能提高。浸泡实验结果表明,该涂层有利于诱导羟基磷灰石的形成,从而提高涂层的生物活性。

Formation and Characterization of Hydroxyapatite Coating Prepared by Pulsed Electrochemical Deposition

Hydroxyapatite coatings were prepared on magnesium alloy AZ91D by pulsed electrochemical deposition. The effects of electrochemical deposition parameters such as pulsed voltage, electrochemical deposition time and electrolyte additive on the morphology, the microstructure, the composition, the coating thickness and electrochemical properties were tested. The results show that at 110 V, the coating with lower porosity, more homogeneous surface and nanometer particles can be obtained, which also has higher XRD diffraction peaks. The morphology and the microstructure of hydroxyapatite particles of the samples prepared in Ca-P electrolyte with NaNO3 and H2O2 addition at 110 V are optimized. The corrosion resistance of the prepared coating is enhanced in potentiodynamic polarization and electrochemical impedance tests. Moreover, immersion test results indicate that such a coating is beneficial to hydroxyapatite formation and enhancing the bioactivity in simulated solution.