Naslov
Passive film on orthopaedic TiAlV alloy formed in the physiological solution investigated by X-ray photoelectron spectroscopy

Autori
Milošev, Ingrid ; Metikoš-Huković, Mirjana ; Strehblow, H.-H.

Izvornik
Biomaterials (0142-9612) 21 (2000), 20; 2103-2113

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Ti alloy; electrochemical oxidation; oxide film; XPS; EIS

Sažetak
The passive film formed by electrochemical oxidation on TiAlV alloy in physiological solution was studied using X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). The alloy was polarized at different oxidation potentials in electrochemical chamber attached top the spectrometer. Thus the composition of the layer formed by oxidation was analyzed by XPS without prior exposure to air (quasi-in situ). The oxide layer was predominantly TiO_2, which contained a small amount of suboxides TiO and Ti_2O_3 closer to the inner metal/oxide interface. With increasing potential the content of Ti^4+ species increased and that of Ti^3+ and Ti^2+ decreased. The content of titanium in TiO_2 was lower than theoretically predicted due to the incorporation of Al_2O_3 in TiO_2 matrix. Vanadium oxide was not identified by XPS. Angular resolved XPS analysis confirmed that Al_2O_3 is located mainly at the outer oxide/solution interface. The thickness of the oxide layer was dependent on the oxidation potential and after oxidation at 2.5 V reached 9 nm. EIS measurements were used to in situ characterise electronic properties of passive films over seven decades of frequency. A link between electronic, electrochemical and physiochemical properties was established.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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