Atomic layer-deposited TiO.sub.2./sub. coatings on NiTi surface

0501809 - FZÚ 2019 RIV US eng J - Článek v odborném periodiku
Vokoun, David - Racek, Jan - Kadeřávek, Lukáš - Kei, C.C. - Yu, Y.S. - Klimša, Ladislav - Šittner, Petr
Atomic layer-deposited TiO₂ coatings on NiTi surface.
Journal of Materials Engineering and Performance. Roč. 27, č. 2 (2018), s. 572-579. ISSN 1059-9495. E-ISSN 1544-1024
Grant CEP: GA ČR GB14-36566G
Institucionální podpora: RVO:68378271
Klíčová slova: atomic layer deposition * corrosion * mechanical tests * NiTi * sem * TiO₂
Obor OECD: Coating and films
Impakt faktor: 1.476, rok: 2018

NiTi alloys may release poisonous Ni ions at the alloys surface. In an attempt to prepare a well-performing surface layer on an NiTi sample, the thermally grown TiO2 layer, which formed during the heat treatment of NiTi, was removed and replaced with a new TiO2 layer prepared using the atomic layer deposition (ALD) method. Using x-ray photoelectron spectroscopy, it was found that the ALD layer prepared at as low a temperature as 100 C deg. contained Ti in oxidation states + 4 and + 3. As for static corrosion properties of the ALD-coated NiTi samples, they further improved compared to those covered by thermally grown oxide. The corrosion rate of samples with thermally grown oxide was 0,00001053 mm/year, whereas the corrosion rate of the ALD-coated samples turned out to be about five times lower. However, cracking of the ALD coating occurred at about 1.5% strain during the superelastic mechanical loading in tension taking place via the propagation of a localized martensite band.

Trvalý link: http://hdl.handle.net/11104/0293794