Sinthesis of TiO_2 nanotubular films obtained thorugh electrochemical anodization in glycerol-H_2O + NH_4F at high voltage and their corrosion and mechanical performance

摘要

In this work the fabrication of TiO_2 nanotubes films together with their electrochemical (corrosion performance) and mechanical characterization is presented. The fabrication of TiO_2 nanotubular films were made through electrochemical anodization exposing titanium foils in a glycerol-H_2O (50:50 vol. %) +0.27 M NH_4F applying a voltage of 20 volts. The TiO_2 nanotubular films were obtained from two different superficial conditions of titanium: with no polishing and as mirror polishing. The anodization time for the natural titanium was 2:30 h, whereas for the as mirror polishing was 3:30 hr. In order to become the TiO_2 amorphous films into crystalline condition, both films were annealed at two temperatures: 450 and 600°C. The morphology and chemical composition of the TiO_2 nanotubular films were made by means of SEM and DRX. The electrochemical characterization was made using the potentiodynamic polarization curve, while the mechanical characterization was made through nanoindentation. The electrochemical stability of several samples, including that of pure titanium (with pulishing and with no pulishing), Ti with a TiO2 planar layer, and the TiO_2 nanotubular films crystallized at 450 and 600°C in a solution 1M Na_2SO_4 at room temperature was obtained.