Morphology and properties of nanotubular oxide layer on the “Ti–13Zr–13Nb” alloy

The "Ti-13Zr-13Nb" alloy in solid and porous form was oxidised. The constant voltage 20 V, oxidation time 0.5 and 1 h, and 1 M H3PO4 (orthophosphoric acid) with an addition of HF (hydrofluoric acid) as the test conditions were applied. SEM (Scanning Electron Microscope) examinations of surface, EDS (Energy Dispersive X-ray Spectroscopy) chemical analysis, nanohardness and nanoscratch tests, and corrosion potentiokinetic tests at various pH values were performed. Results show that an oxidation of this ternary alloy in acidic solution in the presence of fluoride ions results in the appearance of nanotubular oxide layer of high nanohardness, well adjacent to the base. Oxide film appears both on the surface and within the pores. Different colonies of nanotubes are observed. Obtained results prove that for such alloys, both as solid and porous material, nanotubular oxide layers of suitable morphology, high mechanical properties and enhanced bioactivity may be formed. (C) 2014 Elsevier B.V. All rights reserved.