Preparation of TiO₂ layers on cp‐Ti and Ti6Al4V by thermal and anodic oxidation and by sol‐gel coating techniques and their characterization

Abstract

The excellent biocompatibility of titanium and its alloys used, for example, for medical devices, is associated with the properties of their surface oxide. For a better understanding of the tissue reaction in contact with the oxide layer, knowledge of the chemical and physical properties of this layer is of increasing interest. In this study, titania films were produced on cp-Ti and Ti6Al4V substrates by thermal oxidation, anodic oxidation, and by the sol-gel process. The thickness and structure of the films produced under different conditions were determined by ellipsometry, infrared spectroscopy, and X-ray diffraction measurements. The corrosion properties of these layers were investigated by current density-potential curves under physiological conditions. The oxide layers produced on cp-Ti and Ti6Al4V by thermal oxidation consist of TiO(2) in the rutile structure. For the anodized samples the structure of TiO(2) is a mixture of amorphous phase and anatase. The structure of the coatings produced by the sol-gel process for a constant annealing time depends on the annealing temperature, and with increasing temperature successively amorphous, anatase, and rutile structure is observed. Compared to the uncoated, polished substrate with a natural oxide layer, the corrosion resistance of cp-Ti and Ti6Al4V is increased for the samples with an oxide layer thickness of about 100 nm, independent of the oxidation procedure.

Characterization of Anatase Phase on Calcinated Titanium-V Alloy

“…• C. 3,18,19 The amount of anatase is expected to be greater towards the middle of this range. Therefore, the thermally oxidized samples at 300-450…”

“…It has been shown that both the roughness and thickness of the oxide layer increase with oxidation time. 3,16 Thickness of the surface has also been shown to increase with the temperature to which the sample is exposed.…”

Characterization of TiO2 Nanofilms Obtained by Sol-Gel and Anodic Oxidation

“…Sol-gel dip-coating [5,[13][14][15][16] and anodic oxidation [5,[17][18][19][20][21] are two accessible methods for producing TiO2 coatings because no expensive equipment is required [22]. By controlling the parameters of both techniques, nanofilms with a smooth surface can be obtained.…”

C ion-implanted TiO2 thin film for photocatalytic applications

“…In order to induce the complete oxidation of the titanium layers into TiO 2 , the samples were annealed at 600 C for 30 min in a conventional furnace under a controlled O 2 flux. 21 The thickness and the composition of the TiO 2 films were investigated by Rutherford Backscattering Spectrometry (RBS), with a 3.5 MeV HVEE Singletron accelerator, using a 2 MeV He þ beam with 165 scattering angle. The samples were then implanted with C þ ions at 20 keV, with a fluence of 1 Â 10 15 cm À2 .…”