Biomineralization of Titanium Alloy with Surface Micro- and Nanoscaled Modifications

摘要

The aim of the present study was to characterize two kinds of TiN/TiO_2 coatings in terms of topography, composition, and electrochemical stability after immersion in simulated body fluid (SBF). Micropatterning of the substrate (Ti-5Al-4V alloy) was done by using electron beam modification (EBM) by scanning electron beam while nanostructured TiN/TiO_2 films were deposited over EBM Ti5Al4V substrates using two physical vapor deposition techniques: 1) magnetron sputtering, and 2) cathodic arc and glow-discharge methods. When immersed for 7 and 14 days in SBF at static conditions (37±0.05 °C, pH 7.4), Ca/P ratio of the apatite deposits increased from approximately 1.5 up to near stoichiometric (1.67), respectively. After the initial decrease, the pH of the solution during soaking increased gradually reaching values close to 7.7 for both coatings. However, the weight gain of the samples with Arc coatings after the immersion period in SBF was nearly three times more than those with magnetron deposited coating. The electrochemical potentiodynamic tests performed in SBF indicated a shift in the corrosion potentials towards nobler direction after 7 and 14 days of immersion compared to non-immersed samples, whereas the corrosion current density was slightly increased.