Synthesis and Characterization of Nanostructured Oxide Layers on Ti-Nb-Zr-Ta and Ti-Nb-Zr-Fe Biomedical Alloys

Nanoporous/nanotubular complex oxide layers were developed on high-fraction β phase quaternary Ti-Nb-Zr-Ta and Ti-Nb-Zr-Fe promising biomedical alloys with a low elasticity modulus. Surface modification was achieved by electrochemical anodization aimed at the synthesis of the morphology of the nanostructures, which exhibited inner diameters of 15-100 nm. SEM, EDS, XRD, and current evolution analyses were performed for the characterization of the oxide layers. By optimizing the process parameters of electrochemical anodization, complex oxide layers with pore/tube openings of 18-92 nm on Ti-10Nb-10Zr-5Ta, 19-89 nm on Ti-20Nb-20Zr-4Ta, and 17-72 nm on Ti-29.3Nb-13.6Zr-1.9Fe alloys were synthesized using 1 M H₃PO₄ + 0.5 wt% HF aqueous electrolytes and 0.5 wt% NH₄F + 2 wt% H₂0 + ethylene glycol organic electrolytes.