Thickness of Anodic Titanium Oxides as a Function of Crystallographic Orientation of the Substrate

Abstract

This work deals with the anodization-driven oxidation of titanium, studied as a function of the crystallographic orientation of the crystal grains of the substrate. On a polycrystalline surface, different colors appear on the surface after anodization under galvanostatic conditions at a fixed potential. The color of the oxides on individual grains is correlated to an independent set of reflectometry data relating color to thickness, to infer the approximate thickness of the oxide layer grown on each grain in the polycrystal. These data are further related to the crystallographic orientation of each grain as assessed by electron backscatter diffraction measurements. It is shown that crystallographic orientations close to (0001) lead to relatively slower oxidation as compared with inclined orientations.

Fabrication of Ti substrate grain dependent C/TiO2 composites through carbothermal treatment of anodic TiO2

“…oxygen vacancies. 26,49,50 This is likely to affect the atomic reorganization or diffusion processes during annealing and therewith yield a higher isothermal crystallization rate for TiO 2 on BTi(0001) than for TiO 2 on BTi{hki0}. In particular, a considerable increase of donor density, supported by a parallel increase in the electron transfer rate, oxygen evolution current and photocurrent, has been found for anodic TiO 2 films on top of Ti substrate grains with tilt angles decreasing below F B 451, 25,28 which is in very good agreement with the observed increase of TiO 2 crystallinity for tilt angles F r B501 (see Fig.…”

Anodic oxidation of titanium: from technical aspects to biomedical applications

“…The same factors significantly affect the oxide structure as well: amorphous films are generally obtained, but crystallites may nucleate in the amorphous matrix by increasing the applied voltage over a given threshold, and specifically n air sinθ reflection = n TiO 2 sinθ refraction mλ = 2dsinθ proach offers a deeper insight into the corrosion behavior of polycrystalline titanium (61)(62)(63).…”

Morphological and structural characteristics of orthodontic mini-implants

“…The highest oxygen content in the Vector-TAS™ must be due to its much thicker yellow-colored TiO 2 layer, produced either by anodic oxidation [26], plasma ion implantation [23], or thermal oxidation [44]. Since anodic oxidation is considered the most reliable technique for the color-code identification of titanium implants [11], the Vector-TAS™ may well have been subjected to this treatment. The presence of phosphorus on the latter, a typical impurity from the anodizing liquid, and the increased oxygen content from the increased anodized TiO2 film thickness, support such a claim.…”

“…Die Tatsache, dass Vector-TAS™ den höchsten Sauerstoffgehalt aufweist, sollte der erheblich dickeren, gelbfarbigen TiO 2 -Schicht zugeordnet werden, die entweder durch anodische Oxidation [26], Plasma-Ionenimplantation [23] oder thermische Oxidation [44] entstehen kann. Da die anodische Oxidation als das verlässlichste Verfahren für die farbliche Identifizierung von Titanimplantaten gilt [11], kann angenommen werden, dass Vector-TAS™ dieser Behandlung unterzogen wurde. Diese Annahme wird gestützt durch das Vorliegen von Phosphor bei dem letzteren, eine typische Verunreinigung durch die Anodisierungsflüssigkeit sowie durch den gesteigerten Sauerstoffgehalt aufgrund der erhöhten Dicke der TiO 2 -Schicht.…”