Hydroxyapatite/Titania Nanostructure Biocoating on Ti6Al4V Alloy by Sol-Gel Dip-Coating

The aim of this work is to produce hydroxyapatite (HA) coatings on titanium alloys (Ti6Al4V) for facilitating and shortening the processes towards osseointegration. The TiO2 layer was inserted between Ti6Al4V substrate and HA coating to improve the corrosion resistance of substrate as well as bonding strength between metal substrate and ceramic coating. TiO2 and HA coatings were obtained by sol–gel dip-coating. After preparing of substrates, they dipped into TiO2 sol, and this followed by heat- treatment at different temperatures. Calcination at 400°C for 1h was chosen as optimum condition for heat treatment of TiO2 coatings. Subsequently, the HA layer was coated and heat treated at 350°C for 30 min. X-ray diffraction (XRD) analysis were used to study the phase composition of coatings. Morphology of coatings was also performed using a scanning electron microscope (SEM). The corrosion resistance of samples was assessed by polarization test under simulated body fluid (SBF) at 37°C. The bioactivity of sol–gel coatings was observed during soaking of them inside SBF at 37 °C for 28 days.

Keywords:

:Hydoxyapatite , Titanium substrate , Sol-Gel , Bioactivity