Fabrication and characterization of anodic oxide nanotubes on TiNb alloys

Abstract

Titanium and its alloys have been extensively used as implant materials owing to their high specific strength, good biocompatibility and excellent corrosion resistance. Oxide nanotubular array layer can be formed on Ti alloy surface by electrochemical anodization treatment. In this work, the morphology of nanotubes formed on Ti-Nb alloys (Nb content of 5 wt%, 10 wt%, 20 wt%, 30 wt% and 40 wt%) was investigated using an electrolyte containing ethylene glycol and NH 4 F. Oxide layers consisting of highly ordered nanotubes with a range of diameters (approximately 40-55 nm for the inner diameter and 100-120 nm for the outer diameter) and lengths (approximately 10-20 lm) can be formed on alloys in the Ti-xNb system, independent on the Nb content. The nanotubes formed on the Ti-Nb alloy surface were transformed from the anatase to rutile structure of titanium oxide. The oxide nanotubular surface is highly hydrophilic compared with the intact TiNb foil. The surface wettability varies with the nanotube diameter. As the nanotube diameter increases while the nanotube layer thickness remains constant, the capillary wetting of the nanotube surface decreases and the surface becomes less hydrophilic. Annealing changes the nanotubular surface wettability further and establishes less hydrophilic surface conditions due to the removal of hydroxyl groups and residue fluoridecontaining species. It is believed that the surface wettability is changed due to the decreasing content of hydroxyl groups in ambient atmosphere. This work can provide guidelines for improving structural and environmental conditions responsible for changing surface wettability of TiNb surfaces for biomedical applications.

Surface anodization of the biphasic Ti13Nb13Zr biocompatible alloy: Influence of phases on the formation of TiO2 nanostructures

“…Another important fact that can be observed in Figure 4 is the absence of any other oxide other than TiO2, despite the presence of high amounts of Nb and Zr. Such absence of other oxides was also observed in several works in the literature, for instance for the Ti20Nb [58,59], Ti13Nb13Zr [8], and Ti15Mo [12] alloys. Minor or no explanation at all is given for this fact by the authors of these works.…”

Preparation of Ti-Nb-Fe-O Nanotubes on Ti10NbxFe Alloy and the Application for Photocatalytic Degradation under Solar Irradiation

“…TiA-450 shows the largest tube wall thickness of 24.11 nm, whereas smaller tube wall thicknesses of ~13.16, ~6.58, and ~6.02 nm were observed for the other three samples, respectively. These results, along with the SEM observations, make it clear that ordered self-organized tubes are easier to form on both pure Ti and the Ti10Nb-based alloy [37,41]. The diameter of the nanoparticles on Ti10NbA-450 was about 300 nm, while that of Ti10Nb0.5FeA-450 and Ti10Nb1FeA-450 were both about 200 nm, as shown in Figure 6a-c.…”

Self-organized double-wall oxide nanotube layers on glass-forming Ti-Zr-Si(-Nb) alloys

“…HF containing electrolyte, longer nanotubes were grown on the Ti45Nb alloy than on the pure Ti [21], and in ethylene glycol based electrolytes a Nb content between 5 and 40 wt% in TiNb alloys did not show a significant influence on the nanotube layer thickness [30]. Beside all the above described variations in the data plots, the anodization was completed after 6 hours, with currents on approximately same level.…”

“…However, the impact is relatively small for Ti-Zr alloys with less than 20 wt.% Zr [34]. Looking at the dimensions of nanotube layers grown on Ti-Nb alloys in ethylene glycol electrolytes, the content of Nb does not show an influence on the nanotube length and diameter [30] within the given compositional interval. Finally, the literature for Ti-Zr-Nb reports that when Nb content is fixed and Zr content is increasing (i.e.…”