Electrochemical deposition of hydroxyapatite coatings on titanium

Hydroxyapatite coatings were prepared on titanium substrate by electrochemical deposition technology, in which the electrolyte was 0.042 mol/L Ca(NO3)2 and 0.025 mol/L (NH4)2HPO4 with pH 4.4 adjusted by dilute HNO3 and N4OH. The morphology and phase composition of the coatings were investigated by scanning electron microscopy(SEM) and X-ray diffractometry(XRD). The effect of the deposition voltage and electrolyte concentration on the morphology and the structure of the coating was also discussed. The results show that coating thickness increases and the morphology changes from porous form to actionomprphic-assembled form with increasing deposition voltage(from 1 V to 3 V). In addition, it is found that the anodic oxidation of the titanium is effective in improving the tear strength between the HA coatings and the Ti substrate.