Influence of Annealing Temperature on Corrosion Resistance of TiO2Nanotubes Grown on Ti-30Ta Alloy

With little success, researchers has been searching for alloys with elements such as tantalum to improve the long-term life of implants. The Ti-30Ta alloy presents an elastic modulus E = 69 GPa that is close to that of bone (E = 17-25 GPa) than Ti cp (E = 105 GPa). In addition, nanostructure surface modification influences cell behavior and antimicrobial activity. So, this study investigates the corrosion behavior of surface modification by TiO(2)nanotube grown on Ti-30Ta alloy after anodization process in the electrolyte glycerol + NH4F 0.25% at 30 V, for nine hours without annealing and annealed in 450 degrees C, 530 degrees C and 600 degrees C (5 degrees C/min). The electrochemical behavior was evaluated by three electrodes cell. The counter-electrode of graphite, reference-electrode of saturated calomel electrode and working-electrode at electrolyte of 0.15 M NaCl + 0.03 M NaF, with pH = 6 for 8000 s. The scanned region ranged from -0.8 V to values up to 3.5 V with a sweep rate 0.166 mV/s. Potentiodynamic polarization curves were obtained with a potentiostat. The sample was characterized by scanning electron microscopy (SEM) imaging, X-ray diffraction analysis (XRD) and wettability with a contact angle goniometer. We concludes from the obtained results that all treatment surfaces are hydrophilic (<90 degrees). The surface covered with TiO(2)nanotube crystallinity showed anatase phase after annealing at 450 degrees C, 530 degrees C and 600 degrees C; the exceptions were the anodized-without-annealing treatment and without-surface-modification alloys. The electrochemical behavior of the five groups investigated showed similar high resistance to corrosion solution under all conditions.