Titanium oxidation for biomedical applications is still a challenge in obtaining favorable mechanical and physicochemical properties of thin oxide layers, as well as the required high bioactivity. Interesting techniques for TiO2 layer formation are electrochemical, plasma and diffusive methods. Each method aims to create a thin oxide layer characterized by thermal stability and re-passivation in the presence of a simulated body fluid SBF environment. However, an important aspect here is also the phase composition of oxide layers, essential for osseointegration. Accordingly, the research carried out aims to produce such a titanium substrate, where the surface zone is a Tiα(O) solid solution formed with fluidized bed (FB) diffusion process (640 °C, 8 h) and the top layer is TiO2 produced by physical vapour deposition PVD—magnetron sputtering. The effects of such hybrid oxidation on titanium surface properties were investigated with scanning electron microscopy SEM/scanning transmission electron microscopy STEM/ Raman spectroscopy RS and nanoindentation tests. The results showed that hybrid oxidation made it possible to generate a favorable synergetic effect between FB and PVD oxide layers and to reduce the stresses at their interface. In turn, a variable share of TiO2 phases (rutile + anatase mixture) obtained at the titanium surface allowed for the significant enhancement of hydroxyapatite compound growth, which was confirmed by a 14-day Kokubo test.
Production of a biofunctional titanium surface using plasma electrolytic oxidation and glow-discharge plasma for biomedical applications
