Characterization and corrosion resistance of plasma sprayed HA and HA-SiO2 coatings on Ti-6Al-4V

The objective of this study is to evaluate corrosion resistance of plasma sprayed hydroxyapatite (HA) and hydroxyapatite-silicon oxide (SiO2) coated Ti-6Al-4V substrate. In HA-SiO2 coatings, 10 wt.% SiO2 was mixed with HA. The feedstock and coatings were characterized by X-ray diffraction and scanning electron microscopy/energy dispersive X-ray spectroscopy. The corrosion resistance was determined for the uncoated and two coatings. The corrosion resistance of the Ti-6Al-4V was found more after the deposition of the HA + 10 wt.% SiO2 rather than after HA coating and uncoated. Both HA, as well as, HA + 10 wt.% SiO2 coatings were crack free after 24 h dipping in Ringer's solution for electrochemical corrosion.