Surface characterization of plasma sprayed pure and reinforced hydroxyapatite coating on Ti6Al4V alloy

Hydroxyapatite coatings suffer from poor mechanical properties like fretting fatigue, toughness and abrasive wear resistance. These properties can be enhanced by incorporation of secondary ceramic and metallic reinforcements in HA. An attempt has been made to deposit HA and HA reinforced with 10 wt.% (80Al2O3–20TiO2) by plasma spray process on Ti6Al4V substrate. These coatings have been characterized using SEM/EDAX, XRD and FTIR spectroscopy. Corrosion studies have been done in SBF solution. Bio compatibility study is not included in this work. Reinforcement has enhanced the tensile strength. There is marginal improvement in microhardness and surface roughness with reinforcement. Both pure and reinforced coatings show superior resistance against corrosion in simulated body fluid.

Research Highlights
► 10 wt.% alumina–titania reinforced HA coating has comparatively superior mechanical properties like, tensile strength, micro hardness etc. than pure HA coating.
► Microstructure properties of HA coating for bio implants improves with reinforcement of 10 wt.% alumina–titania.
► Non amorphous phases in both pure and reinforced coating observed with plasma spray coating technique.
► Corrosion resistance of pure HA coating was higher than that of reinforced HA coating.