Properties of composite oxide layers on the Ti13Nb13Zr alloy

Abstract

The development of composite oxide layers on the Ti13Nb13Zr alloy, their structure and properties, were demonstrated. Two subsequent methods were applied to prepare the composite layers. During the first stage, gas oxidation produced a dense compact oxide layer, and subsequent oxide nanotubes were formed applied an electrochemical oxidation. The scanning electron microscopy, energy-dispersive X-ray spectroscopy, electrochemical impedance spectroscopy, and Raman spectroscopy were used to examine the appearance, thickness, chemical and phase composition of the oxide layers. The results obtained revealed that the composite layers composed of two zones. The electrochemical formation of the outer nanotubular oxide zone occurred if the thickness of the first inner oxide zone was small enough because of resistance increasing with the inner zone thickness followed by a decrease in electrochemical reaction rate. The decreasing corrosion resistance of the Ti13Nb13Zr alloy was observed and explained by a model electric circuit.

The Morphology, Structure, Mechanical Properties and Biocompatibility of Nanotubular Titania Coatings before and after Autoclaving Process

“…The highest value of H 2 /E 3 was noticed for Ti6Al4V specimens (0.058 GPa), which suggests better tribological properties of reference specimen than TNT and TNH layers [52]. Nanoscratch-test was used in the past to study adhesion of thin oxide layer on titanium alloys [53,54]. Adhesion between the layer and the implant surface is one of the most important factors deciding on the possibility of using this modification technique for the biomaterials.…”

Influence of Two-Stage Anodization on Properties of the Oxide Coatings on the Ti–13Nb–13Zr Alloy

“…The two-stage oxidation could result in the bi-layer ("sandwich" layer) oxide coating as shown in [47] in which the alloy was subjected to gaseous oxidation and then to the electrochemical oxidation. The last method performed in the presence of HF acid caused the transformation of the upper part of the compact oxide coating into a nanotubular layer, resulting in both highly corrosion-resistant and bioactive coating.…”

“…All measurements were performed at room temperature. The anodization parameters were set up based on some earlier investigations [47]; in particular, even if the electrochemical oxidation time has a small effect on the oxide thickness, the 30 min period was assumed necessary to perform the electrochemical oxidation at equilibrium conditions.…”

“…The low potential electrochemical oxidation may result in either the compact oxide [44] or nanotubular oxide coatings, depending on the type of electrolyte and anodization parameters [45][46][47][48][49][50][51][52][53][54][55]. The TiO 2 nanotubular surface provided topography favorable for improving the clinical performance of implants when comparing to the sand-blasted acid-etched topography [56].…”

“…The oxides obtained by low voltage anodization can be in the form of thin, compact coatings or nanotubular layers. In the past, the bi-layer coating was prepared [47] by gas oxidation of titanium alloy and then electrochemical oxidation resulting in nanotubular layers grown on the previous compact oxide layer. Such treatment brought out the highly corrosion-resistant coatings but possessing the relatively short nanotubes.…”