Preparation and characterization of nanocrystalline calcium phosphate/Al₂O₃-Ti biocomposite

This work aims at developing a new and reliable biomaterial for implant application by fabricating calcium phosphate/Al₂O₃ biocomposite coating on medical titanium using a hybrid technique of anodic oxidation and hydrothermal treatment. The pre- and post-anodized samples were investigated by scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDAX), transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. The results indicated that porous anodic alumina film containing Ca and P was obtained on the as-prepared Al-Ti substrate through anodization, and the subsequent hydrothermal treatment led to the formation of calcium phosphate crystals. SEM and TEM results showed that calcium phosphate crystals were in nanometer, in-situ embedded in the walls of the cylindrical structure of anodic alumina, and finally formed a thin and porous top layer on the anodic alumina layer. The nanometer effect of calcium phosphate top layer, the porous and cylindrical microstructure of calcium phosphate/Al ₂O₃-Ti, and the in-situ growth effect are expect to possess a very good combination of bioactivity and mechanical integrity.