Thick hydroxyapatite coatings by electrophoretic deposition

Abstract Submicron hydroxyapatite (HA) powders prepared by thermal plasma spray method were electrophoretically deposited on carbon rod by repeated depositions at room temperature. The thickness of green coating was adjusted by deposition time and the number of depositions. After sintering, a uniform HA ceramic tube was obtained. A range of sintering temperature from 1150 to 1300 °C was studied. From the Fourier transform-infrared (FT-IR) spectra and SEM results, the sintering temperature has shown an obvious influence on the microstructure and densification, hence the strength of the sintered coatings. No HA decomposition was observed up to 1300 °C of sintering by X-ray diffraction (XRD) analysis. The influence of processing factors such as electrophoretic mobility of particles, suspension concentration, applied electric field and deposition time on coating behavior was also discussed.