Influence of thermal treatment on the roughness, corrosion resistance and wettability of hydroxyapatite films deposited by RF magnetron sputtering

In this paper we report on the preparation and characterization of hydroxyapatite coatings deposited on Ti6Al4V alloy by magnetron sputtering deposition method. The amorphous deposited coatings were thermal annealed in a flux of dry nitrogen and water vapours at 800 °C for 30 and 120 minutes, in order to investigate the effect of this treatment on surface roughness, corrosion resistance and wettability. The films were characterized by surface profilometry, electrochemical tests and contact angle measurements. After annealing, the hydroxyapatite coatings became crystalline, exhibiting rougher surfaces, higher corrosion resistance and lower contact angles. We have demonstrated that the hydroxyapatite coating annealed at 800°C for 30 minutes represents a good candidate to be used for medical implants, due to its superior corrosion behaviour and good wettability.