Various Morphologies Hydroxyapatite Crystals on Ti MAO Film Prepared by Hydrothermal Treatment

Hydroxyapatite crystals of various morphologies were grown on Ti-6Al-4 V plates using Micro-arc oxidation (MAO) plus hydrothermal treatment. Phase identification was carried out by XRD. The mechanisms by which these HA crystals form is here discussed. It was deduced that HA formation depended on the degree of supersaturation of Ca and P ions in the treated solution. Various hydrothermal treatments with different degrees of supersaturation were designed and performed. Crystals with flake, needle-like, hexagonal column, and composite morphologies were obtained. The formation of different HA morphologies is discussed in terms of growth mechanisms. The effects of the degree of supersaturation of Ca and P ions on the morphologies of hydroxyapatite crystals are illustrated.