Corrosion products generated in artificial pits of zirconium were characterized in-situ by synchrotron X-ray diffraction and X-ray absorption near edge structure (XANES) in physiological saline, with and without addition of 4% albumin and/or 0.1% H2O2. Zr metal fragments and tetragonal ZrO2 particles were detected in aggregated black corrosion products away from the corrosion front. At the corrosion front, a ZrOCl2·8H2O salt layer of a few hundreds of microns thickness was formed. Coarsened ZrOCl2·8H2O crystallites were found farther out into the solution. The Zr solution species were confirmed to be in a tetravalent state by XANES. TEM imaging of the corrosion products revealed heterogeneity of the morphology of the Zr metal fragments and confirmed their size to be less than a few microns. The formation and speciation of Zr corrosion products were found not affected by the presence of H2O2 and/or albumin in physiological saline. Furthermore, bulk Zr electrochemistry identified that the presence of H2O2 and/or albumin did not affect passive current densities and pitting potentials of the bulk Zr surface. Therefore, it is concluded that the pitting susceptibility and pit chemistry of Zr in physiological saline were unaffected by the presence of H2O2, albumin or their combinations.
|Journal||Journal of the Electrochemical Society|
|Publication status||Published - 1 Dec 2017|
Bibliographical note© The Author(s) 2017. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. [DOI: 10.1149/2.0671714jes] All rights reserved.
Funding: National Institute for Health Research, award No. NIHR/CS/010/001, postgraduate research scholarship from the University of Birmingham School of Metallurgy and Materials, European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 659226.