Abstract
In recent studies, titania has been added to hydroxyapatite (HA) coatings to impart photocatalytic properties. The benefits of such additions are maximized when titania is in nanocrystalline anatase form. In this study, nano-titania was synthesized in-flight from a liquid precursor consisting of ethanol and titanium isopropoxide. The precursor and HA powder were fed into a plasma gun, forming nano-titania particles that embedded in the HA. Coatings of pure titania and titania-embedded HA were deposited under different spray conditions on titanium coupons and then characterized via XRD and SEM analysis. The titania coatings contained ultrafine anatase and rutile particles with anatase being favored by more power input and rapid quenching. The composite coatings contained dispersed ultrafine titania particles in a matrix consisting primarily of HA with trace amounts of calcium phosphate and amorphous phases. The effect of spraying parameters on phase and microstructure evolution is discussed as well.