Characterization of TiO2 films made by anodic oxidation on Ti-6Al-4V

VERA, M.L.; ARES, A.E.; MARIO ROBERTO ROSENBERGER; LAMAS, DIEGO; SCHVEZOV, C. E.

Campinas

Encuentro; 20ma Reunión Anual de Usuarios: Laboratorio Nacional de Luz Sincrotron (LNLS); 2010

The Ti-6Al-4V alloy is widely used as a structural material due to its excellentmechanical and corrosion resistant properties. At present they are also used inmechanical prosthetic devices for human implants due to the excellent biocom-patibility. The bio and chemical properties of titanium alloys are known to beassociated to the formation of TiO2 on the surface which occurs naturally. Ox-ide ¯lms in metals can also be produced by anodic oxidation, resulting in ¯lmswhich may be thicker and denser than the natural oxides [1-3]. In this work TiO2¯lms on Ti-6Al-4V substrates were produced by anodic oxidation, using a H2SO41 M solution as electrolyte at di®erent voltages (from 10V to 70V). Thickness andphase composition of the ¯lms were determined by X-ray re°ectometry and X-raydi®raction, respectively. These experiments were carried out at the D12A-XRD1beamline of the LNLS. The results of the in°uence of voltage on color, thickness,morphology and crystalline structure of the oxides are presented which are neces-sary to analyze for the production of coatings for biomedical applications. TiO2¯lms of di®erent colors were obtained, with thickness ranging from 20 to 200 nmdepending on the applied voltage. Relationships among voltage, color and thicknesswere con¯rmed. The ¯lm roughness is of the order of the substrate roughness and itincreases with the applied voltage. The oxide layers produced at low voltages up to50V are smooth and amorphous. A spark discharge occurs, at voltages larger than60V, producing porous and crystalline (anatase and rutile) coatings. Each of thesemorphologies and structures of the coatings are suitable to di®erent biomedicalapplications and devices.[1] D. Velten, V. Biehl, F. Aubertin, B. Valeske, W. Possart, and J. Breme,Journal of Biomedical Material Research, 59 (2002), 18-28. [2] A.K. Sharma, ThinSolid Films, 208 (1992), 48-54. [3] M.V. Diamanti, and M.P. Pedeferri, CorrosionScience, 49 (2007), 939-948.