Tantalum coating inhibits Ni-migration from titanium out-diffusion in NiTi shape memory biomedical alloy
| Autor: | Sergey Beloshapkin, Syed A. M. Tofail, M.S. Dhoubhadel, Karrina McNamara, K.M. Hossain |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Scanning electron microscope Tantalum General Physics and Astronomy chemistry.chemical_element 02 engineering and technology Surfaces and Interfaces General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Rutherford backscattering spectrometry 01 natural sciences Shape memory alloy 0104 chemical sciences Surfaces Coatings and Films Biomedical alloy Minimally X-ray photoelectron spectroscopy chemistry Chemical engineering Nickel titanium Sputtering Transmission electron microscopy 0210 nano-technology Titanium |
| Popis: | peer-reviewed Despite the presence of over 56% Ni by weight, equiatomic NiTi is generally considered biocompatible as it naturally oxidises to form a surface oxide mainly composed of biocompatible oxides of titanium (TiOx). This layer is formed by an oxidation mechanism that promotes out-diffusion of Ti leaving a Ti-depleted, Ni rich subsurface.The long-term in vivo stability of the naturally grown Ti Oxlayer has been a concern as Ni can leach out through this thin, defective layer. The leaching of nickel (Ni) is thus a continuing threat to the alloy’s other wise outstanding bio compatibility. We have found that a layer of reactively sputtered tantalum(Ta)oxide on the bulk NiTi restricts Ti-out-migration through a biocompatible Ti/Tainter-diffusion layer that provides a larger barrier against Ni leaching. We have investigated this inter-diffusion as a function of sputtering process parameters and post processing treatments. Surface and interface analytical techniques such as X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, cross sectional transmission electron microscopy and non-destructive ion beam analysis techniques such as Rutherford backscattering spectrometry and particle induced X-ray emission were used to evaluate the nature of this interdiffusion layer which can improve long-term biocompatibility of NiTi |
| Databáze: | OpenAIRE |
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