Al-Ti基体上纳米网状钙磷陶瓷/多孔Al2O3生物复合涂层的原位生长

先采用PVD法在医用钛金属表面沉积一层Al膜,得到Al-Ti基体材料;而后采用阳极氧化与水热合成复合制备技术在Al-Ti基体上成功构造了由纳米网状磷酸盐组成的钙磷生物陶瓷/Al2O3多孔复合生物涂层.利用扫描电镜(SEM)、透射电镜(TEM)、电子能谱(EDAX)、X射线衍射(XRD)表征了阳极氧化前后铝膜和钙磷生物陶瓷涂层的微观形貌、元素构成以及晶相成分.结果表明:在阳极氧化过程中,钙、磷元素嵌入阳极氧化铝(AAO)膜,并经水热处理反应原位生成钙磷陶瓷;钙磷陶瓷晶体从Al2O3孔洞长出并覆盖于多孔氧化膜的表面;最终获得的钙磷生物陶瓷/多孔Al2O3复合涂层具有纳米网状、多孔的结构特征.分析探讨了钙磷生物陶瓷/多孔Al2O3复合涂层的原位生长过程,浓度梯度与电位差分别是Ca、P元素进入AAO膜的主要推动力.

In-situ growth of nanometric network calcium phosphate/porous Al2O3 biocomposite coating on Al-Ti substrate

Pure Al thin film was PVD-deposited on medical titanium to form Al-Ti substrate. Al-Ti substrate was then applied to the hybrid technique of anodization and hydrothermal treatment, which finally led to the successful fabrication of nanometric network calcium phosphate/porous Al_2O_3 biocomposite coating on Al-Ti substrate. Scanning electron microscopy(SEM), transmission electron microscopy(TEM), energy-dispersive X-ray analysis(EDAX) and X-ray diffraction(XRD) were employed to study the microstructures and compositions of Al thin film and calcium phosphate/porous Al_2O_3 biocomposite coating. The results indicate that the Ca and P ions are incorporated into the anodized alumium oxide(AAO) during the anodization process, and the incorporated Ca and P are reacted to be calcium phosphate after hydrothermal treatment. The calcium phosphate grows from the holes of AAO and covers the surface of AAO layer. In addition, the mechanism for the in-situ growth process of calcium phosphate/porous Al_2O_3 biocomposite coating was discussed. The concentration gradient and potential difference contribute to the incorporation of Ca and P into AAO film, respectively.