微弧氧化法在纯钛表面生成含羟基磷灰石陶瓷膜的研究

Coatings containing hydroxyapatite fabricated by microarc oxidation on pure titanium

目的:利用微弧氧化法在纯钛表面直接生成含羟基磷灰石的陶瓷膜。方法:通过微弧氧化技术,采用双相脉冲电源,以0.4mol/L醋酸钙和0.2mol/L磷酸二氢钠为电解液体系,设定脉冲频率为60Hz,正相电流密度为20A/dm2,处理时间分别为5min、10min、20min、30min、60min,在纯钛表面制备陶瓷膜。利用扫描电镜观察膜层的表面形貌,能谱仪分析氧化膜的元素组成,X射线衍射仪分析膜层的相组成,电涡流涂层测厚仪测量膜层的厚度。结果:以0.4mol/L醋酸钙和0.2mol/L磷酸二氢钠为电解液体系,经微弧氧化处理后,在纯钛表面形成含有Ti、O、Ca和P元素的微孔结构的氧化膜,该膜由锐钛矿型TiO2、金红石型TiO2及羟基磷灰石组成。随微弧氧化反应时间的延长,膜层增厚,膜层表面微孔孔径增大,数量减少,粗糙度增大。钛元素的相对含量减少,Ca、P元素相对含量增加,O元素变化不明显。钛、锐钛矿型TiO2和金红石型TiO2的衍射峰逐渐减弱,羟基磷灰石的衍射峰逐渐增强。结论:应用微弧氧化技术,以0.4mol/L醋酸钙和0.2mol/L磷酸二氢钠为电解液体系,在纯钛表面能直接生成含有羟基磷灰石成份的微孔结构的陶瓷膜。

Objective： To fabricate coatings containing hydroxyapatite with microarc oxidation （MAO） on pure titanium. Method： Microarc oxidation was performed by using the pulse power. The electrolyte containing 0.4 M CA and 0.2 M NaH2PO4·2H2O was used in the experiment to fabricate oxide coatings. Anodic current density was 20 A/dm^2, and the pulse frequency was 60 Hz for 5 min, 10 min, 20 min, 30 rain, 60 rain, respectively. The phase, morphology and composition of the oxide coatings were monitored with X-ray diffraction （XRD） and scanning electron microscopy （SEM） with energy dispersive X-ray spectrometer （EDS）. Result： The chemical compositions of the MAO coatings were Ti, O, Ca and P. The phases of the coatings were composed of futile TiO2, anatase TiO2, and hydroxyapatite. The thickness of the films increased with the increasing of reacting times. With the increasing of reacting times, the number of micro-pore on the surface of MAO coatings decreased, but pore size and the roughness of surface increased. With the increasing of reacting times, element of Ti decreased, elements of Ca and P increased,element of O unchanged. Hydroxyapatite increased, however, Ti,rutile TiO2 and anatase TiO： decreased with the increasing of reacting times. Conclusion： The coatings containing futile TiO2, anatase TiO2, and hydroxyapatite on pure titanium are formed by microarc oxidation. The electrolyte contains 0.4 M CA and 0.2 M NaH2PO4 ·2H2O.