Nanomechanical properties of bioactive films grown on low energy ion implanted Ti

Surface modification processes such as the alkali-heat treatment (AHT) can be employed in order to improve the titanium osseointegration with living tissues. Sodium titanate films produced by AHT presented high in vitro bioactivity when soaked in simulated body fluid. In order to produce bioactive surfaces and also improve the tribo-mechanical response of AHT films grown on Ti, samples were submitted to H, N and O low energy ion implantation (glow discharge—GD) at different working conditions. AHT film with thickness of 1 μm was produced on untreated Ti and had low hardness (0.012 GPa) as well as low critical nanoscratch resistance (5.5 mN). For the studied periods up to 30 days no in vitro bioactivity was observed on the only GD worked surfaces. Hydrogenated and nitrided Ti became bioactive after the AHT, but the film thickness decreases in comparison to untreated GD Ti. At the same time its critical nanoscratch resistance and bioactivity degree decrease. However for GD oxidized sample an AHT film was not formed. From these results it can be suggested that plenty availability of metallic Ti at the surface is required to grow AHT films with good bioactivity response.