In this work, the anodic formation of self-organized nanotubular oxide layers on Ti13Zr13Nb implant alloy was presented. Anodic oxidation was carried out at room temperature in [1 M] (NH4)2SO4 solution with 1 wt% content of NH4F. The voltage and time of anodization was 20 V for 120 min, respectively. Under proposed conditions, the best arrangement of nanopores was observed. The physical and chemical properties of the anodized surface of the Ti13Zr13Nb alloy were characterized using grazing incidence X-ray diraction, scanning transmission electron microscopy, and atomic force microscopy. It was found that diameter of nanopores varied from 10 to 32 nm. Mechanism of the fabrication of the unique 3D tube-shaped nanostructure of TiO2 on the surface of the Ti13Zr13Nb alloy by electrochemical anodization, has been discussed.

EvaluatIon of corrosIon rEsIstancE of nanotubular oxIdE layErs on thE ti13Zr13nb alloy In physIologIcal salInE solutIonOcena OdpOrnOści kOrOzyjnej nanOtubularnych struktur tlenkOwych na stOpie ti13Zr13nb w śrOdOwisku płynów ustrOjOwych"Evaluation of corrosion resistance of the self-organized nanotubular oxide layers on the Ti13Zr13Nb alloy, has been carried out in 0.9% NaCl solution at the temperature of 37ºC. Anodization process of the tested alloy was conducted in a solution of 1M (NH4)2SO4 with the addition of 1 wt.% NH4F. The self-organized nanotubular oxide layers were obtained at the voltage of 20 V for the anodization time of 120 min. Investigations of surface morphology by scanning transmission electron microscopy (STem) revealed that as a result of the anodization under proposed conditions, the single-walled nanotubes (SwNTs) can be formed of diameters that range from 10 to 32 nm. Corrosion resistance studies of the obtained nanotubular oxide layers and pure Ti13Zr13Nb alloy were carried out using open circuit potential, anodic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. It was found that surface modification by electrochemical formation of the selforganized nanotubular oxide layers increases the corrosion resistance of the Ti13Zr13Nb alloy in comparison with pure alloy.

This paper deals with the basic theory and the usability of the scanning Kelvin probe (SKP) being a non-destructive, non-contact method for testing the condition of the surface of conductor, semiconductor and dielectric samples. This technique is based on the electron work function (EWF) characteristic of various test substances and depends, inter alia, on the sample surface condition. During measurement, the so-called surface potential distribution map containing information about EWF value is registered. Key applications of SKP and its various modifications to characterization of corrosion interfaces, have been presented based on the newest literature data covering the past two years of the active research in the field of corrosion in a nanoscale.

The NiTi alloy (50.6 at.% Ni) passivated for 30 min at 130°C by autoclaving has been studied towards corrosion resistance in aqueous solutions of 3% NaCl, 0.1 M H2SO4, 1 M H2SO4 and HBSS. Structure and thickness of the passive layer (TiO2, rutile) were examined by X-ray reflectivity method and high resolution electron microscopy. Corrosion behavior of this oxide layer was investigated by open circuit potential method and polarization curves. It was found that the corrosion resistance of the passivated NiTi alloy is strongly dependent on the type of corrosive environment. The higher corrosion resistance of the tested samples was revealed in sulfate solutions as compared to chloride ones. The highest resistance to electrochemical corrosion of the NiTi alloy was observed in 0.1 M H2SO4 solution. Susceptibility to pitting corrosion of the tested samples was observed which increased with the concentration rise of chlorine anions in solution. Electrochemical tests for 316L stainless steel carried out under the same experimental conditions revealed a weaker corrosion resistance in all solutions as compared to the highly corrosion resistant NiTi alloy.

This work presents the basic theory and the usability of the scanning vibrating electrode technique (SVET), especially in the field of corrosion. At present, SVET is to be considered as one of the latest electrochemical testing methods. The essence of determining the current density resulting from corrosion is limited to the measurement of the potential gradient between the two points on the surface of the metal and over it, within the electric field of a local element. SVET has been used to study local, galvanic and intercrystalline corrosion. It is particularly useful in studying the corrosion of alloy steels and welding agents. This paper presents a review of the literature on the newest research in this field.