Comparison of 316L and Ti6Al4V biomaterial coated by ZrCu-based thin films metallic glasses: Structure, morphology, wettability, protein adsorption, corrosion resistance, biomineralization

In this study, ZrCu-based thin films were obtained using a PVD-cathodic arc technique, aiming to improve the surface properties of 316L stainless steel and Ti6Al4V implant materials. By combining their superior mechanical properties with the corrosion resistance of amorphous metallic glasses, the obtained ZrCu-based layers could be qualified as candidates for medical applications. Ca, Mo, Mg, Si and Sr additions to ZrCu structure were considered and the resulting ternary systems were subjected to a detailed investigation. Potentiodynamic polarization was employed to assess corrosion kinetics and their overall electrochemical behaviour after 1 h immersion in SBF solution, the experiments being conducted at human body temperature (37.0 ± 0.5 °C). Additionally, electrochemical impedance spectroscopy (EIS) was carried out for detecting fast changes of the system under investigation and to reveal in depth information related to coating/substrate–solution interface. For morphology and topography characterization before and after electrochemical tests, scanning electron microscopy was used. The results showed a dependence of mechanical properties on the used substrate: the hardness was higher and a better adhesion was achieved when Ti6Al4V was used. Immersion tests were also influenced by the substrate related outcome, since the coatings deposited on 316L substrate showed a significant degradation compared to those on Ti6Al4V substrate, where the apatite structure formed on the surface was more evident. ToF-SIMS analysis revealed protein adsorption enhanced for all applied coatings.