In-Situ Synchrotron X-ray Characterization of Corrosion Products in Zr Artificial Pits in Simulated Physiological Solutions

Abstract

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% H 2 O 2 . Zr metal fragments and tetragonal ZrO 2 particles were detected in aggregated black corrosion products away from the corrosion front. At the corrosion front, a ZrOCl 2 ·8H 2 O salt layer of a few hundreds of microns thickness was formed. Coarsened ZrOCl 2 ·8H 2 O 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 H 2 O 2 and/or albumin in physiological saline. Furthermore, bulk Zr electrochemistry identified that the presence of H 2 O 2 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 H 2 O 2 , albumin or their combinations.

In Situ Synchrotron X‐Ray Diffraction Characterization of Corrosion Products of a Ti‐Based Metallic Glass for Implant Applications

“…This is consistent with our recent finding that ZrOCl2•8H2O is generated in artificial pits on pure Zr in 0.9% NaCl. [39] Cu2O appears to form at 0 V close to the interface (Figure 2 and Figure 3b). Cu2O is stable in neutral and alkaline media and might have formed by oxidation of Cu in the metallic glass or hydrolysis of CuCl in either case indicating an increase in pH.…”

Addressing uncertainties in correlative imaging of exogenous particles with the tissue microanatomy with synchronous imaging strategies

“… 30 For example, X-ray absorption spectroscopy and X-ray scattering techniques can be used to define chemical speciation of elements and structural information within the specified region of interest. 31 As understanding the chemical speciation of elements is essential for determining biological reactivity, this is a significant advantage of X-ray-based modalities over destructive mass spectrometry approaches. 7 Mass filtering is routinely applied to IMC to improve detection sensitivity of lanthanides.…”