Insight into Surface Properties of Anodic Oxidized Ti6Al7Nb Alloy for Biomedical Applications

The Ti6Al7Nb alloy is increasingly applied as a vanadium-free alternative to Ti6Al4V for biomedical implants; however, implant performance is governed predominantly by the physicochemical properties of the surface layer. In this study, anodic oxidation was employed as a controlled surface engineering process to generate a functional oxide layer on Ti6Al7Nb alloy and to modify its structural, chemical, and electrochemical characteristics. The anodically formed surface layer was comprehensively characterized in terms of surface morphology, wettability, microhardness, crystallographic phase composition, electrochemical behavior, and surface chemistry combined with depth profiling analysis. In addition, the biological response of the modified surface was assessed using in vitro cytotoxicity tests. The results confirm the formation of a stable and chemically defined oxide layer with enhanced electrochemical stability and tailored surface properties. The modified surface exhibits improved corrosion resistance, controlled physicochemical parameters, and favorable cytocompatibility. These findings demonstrate that anodic oxidation enables precise engineering of the surface layer and highlight its key role as a functional interface controlling implant-environment interactions, confirming this approach as an effective strategy for the development of advanced Ti-based biomedical implant surfaces.