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Corrosion resistance, chemistry, and mechanical aspects of Nitinol surfaces formed in hydrogen peroxide solutions

TitleCorrosion resistance, chemistry, and mechanical aspects of Nitinol surfaces formed in hydrogen peroxide solutions
Publication TypeJournal Article
Year of Publication2012
AuthorsShabalovskaya SA, Anderegg JW, Undisz A, Rettenmayr M, Rondelli GC
Journal TitleJournal of Biomedical Materials Research Part B-Applied Biomaterials
Volume100B
Pages1490-1499
Date Published08
Type of ArticleArticle
ISBN Number1552-4973
Accession NumberWOS:000305972800005
Keywordsastrocyte, biocompatibility, corrosion, cyclic potentiodynamic and, hydrogen peroxide surface treatment, implants, localized corrosion resistance, ni-ti alloy, nickel, nitinol, oxidation, potentiostatic polarization, shape-memory alloy, titanium, under stress, WIRES
Abstract

Ti oxides formed naturally on Nitinol surfaces are only a few nanometers thick. To increase their thickness, heat treatments are explored. The resulting surfaces exhibit poor resistance to pitting corrosion. As an alternative approach to accelerate surface oxidation and grow thicker oxides, the exposure of Nitinol to strong oxidizing H2O2 aqueous solutions (3 and 30%) for various periods of time was used. Using X-Ray Photoelectron Spectroscopy (XPS) and Auger spectroscopy, it was found that the surface layers with variable Ti (615 at %) and Ni (513 at %) contents and the thickness up to 100 nm without Ni-enriched interfaces could be formed. The response of the surface oxides to stress in superelastic regime of deformations depended on oxide thickness. In the corrosion studies performed in both strained and strain-free states using potentiodynamic and potentiostatic polarizations, the surfaces treated in H2O2 showed no pitting in corrosive solution that was assigned to higher chemical homogeneity of the surfaces free of secondary phases and inclusions that assist better biocompatibility of Nitinol medical devices. (c) 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 14901499, 2012
URL<Go to ISI>://WOS:000305972800005
DOI10.1002/jbm.b.32717
Alternate JournalJ. Biomed. Mater. Res. Part B