Influences of Different Surface Treatments on Titanium Substrate to HA/TiO₂ Bioactive Coatings

Abstract

The porous titanium alloy containing 17.5 wt% molybdenum elements prepared by gel-casting methods was used as precursor. The composite coatings with hydroxyapatite and TiO2prepared on the precursor was treated respectively by NaOH solution, 30% H2O2+NH3solution, HF+HNO3and PdCl2solution to improve the characterization of coatings. The microstructure was examined by SEM, and part of the coatings was examined by EDS to indicate the linear distribution of HA and TiO2. The corrosion behavior of the coatings in the simulated body fluids (SBF) was evaluated by potentiodynamic polarization test and impedance plots. The results showed that the corrosion resistance of the coatings treated with PdCl2solution was better than the others. The passivation layer which played a key role in corrosion resistance was generated by PdCl2solution treatment; their surface morphologies was more uniform than the others and had no crack; the thickness of the coatings was 60~70μm.

Preparation of HA/TiO2 biological coating on titanium alloy

“…Titanium alloy has excellent properties such as good corrosion resistance, biocompatibility and so on. It can be used in the manufacture of medical apparatus and instruments, prosthesis and auxiliary treatment equipment etc., which is one of the widely used metal implant materials [5][6]. HA coated to titanium alloy surface not only has a good biological activity, but excellent mechanical properties of titanium alloy substrate and good biological properties of HA ceramics, which has become a hot topic of current biomedical materials research [7][8].…”