Author/Editor		Kocijan, Aleksandra; Milošev, Ingrid; Pihlar, Boris
Title		Cobalt-based alloys for orthopaedic applications studied by electrochemical and XPS analysis
Type		članek
Source		J Mater Sci-Mater M
Vol. and No.		Letnik 15
Publication year		2004
Volume		str. 643-50
Language		eng
Abstract		The composition of the passive layers formed by electrochemical oxidation at different passivation potentials on Co-Cr-Mo and Co-Ni-Cr-Mo alloys in simulated physiological solution (SPS1, with and without the complexing agent EDTA, was studied by X-ray photoelectron spectroscopy. Composition as a function of depth, cationic fraction and thickness of the passive film was determined. Chromium oxide is shown to be the major constituent of the passive layer on both Co-Cr-Mo and Co-Ni-Cr-Mo alloys. The minor constituents of the passive layers, Co- and Mo-oxide in the case of Co-Cr-Mo alloy and Ni-, Co- and Mo-oxides in the case of Co-Ni-Cr-Mo alloy, are also located in the outer part of the layer. EDTA affects the formation of the passive layer on each alloy. The content of Co-, Niand Mo-oxide in the passive layer is lower in the presence of EDTA, thus indicating increased solubility associated with higher stability constants for complexes of metal cations with E DTA.
Descriptors		COBALT CHROMIUM ALLOYS MOLYBDENUM NICKEL EDETIC ACID CORROSION SPECTROMETRY, X-RAY EMISSION IMPLANTS, ARTIFICIAL