Abstract:
Titanium (Ti) and its alloys are widely used as
candidate materials for biomedical implants. Despite their
good biocompatibility and corrosion resistance, these
materials suffer from corrosion after implantation in biological
environments. The aim of this research work is to
study the effect of two coatings on biocompatibility and
corrosion behavior of Ti-6Al-4V biomedical implant
material. Hydroxyapatite (HA) and hydroxyapatite/titanium
dioxide (HA/TiO2) coatings were thermal-sprayed on
Ti-6Al-4V substrates. In the latter case, TiO2 was used as a
bond coat between the substrate and HA top coat. The
corrosion behavior of coated and un-coated samples in
Ringer’s solution was studied by potentiodynamic and
linear polarization techniques. Before and after corrosion
testing, XRD and SEM/EDS techniques were used for the
analysis of phases formed and to investigate microstructure/
compositional changes in the coated specimens. The
cellular response was analyzed by the MTT (microculture
tetrazolium) assay. The results showed that both the HA, as
well as, the HA/TiO2 coatings significantly increased the
corrosion resistance of the substrate material. The HA
coating was found to be more biocompatible as compared
to the un-coated and HA/TiO2-coated Ti-6Al-4V alloy.
