Novel Method of Hydroxyapatite Coating on Titanium Using Chemical Deposition
The aim of this study was to deposit an adherent apatite coating on titanium substrate using a two-step chemical deposition method. First, titanium substrates were immersed in an acidic solution containing calcium and phosphate ions, resulting in the deposition of a monetite (CaHPO4) coating. Second, the monetite crystals were converted to apatite by hydrolysis in NaOH solution. Composition and morphology of the initial and final coatings were identified using X-ray diffraction (XRD), Scanning Electron Microscopy, and Energy Dispersive Spectroscopy (EDS). The final coating was porous and the apatite crystals were agglomerated and followed the outline of the large monetite crystals. The average tensile bond of the coating was 5.2 MPa and cohesion failures were observed more frequently than adhesion failures. The coating adhesion measured using scratch test was 13.1N. In conclusion, this study showed the potential of a two-step chemical deposition method for depositing an adherent coating of apatite at low temperatures.
Guy Daculsi and Pierre Layrolle
R. Rohanizadeh and R. Z. LeGeros, "Novel Method of Hydroxyapatite Coating on Titanium Using Chemical Deposition", Key Engineering Materials, Vols. 361-363, pp. 617-620, 2008