Surface microstructures and corrosion resistance of Ni-Ti-Nb shape memory thin films

Kun Li, Yan Li, Xu Huang, Desmond Gibson, Yang Zheng, Jiao Liu, Lu Sun, Yong Qing Fu

Research output: Contribution to specialist publicationArticle

10 Citations (Scopus)

Abstract

Ni-Ti-Nb and Ni-Ti shape memory thin films were sputter-deposited onto silicon substrates and annealed at 600 °C for crystallization. X-ray diffraction (XRD) measurements indicated that all of the annealed Ni-Ti-Nb films were composed of crystalline Ni-Ti (Nb) and Nb-rich grains. X-ray photoelectron spectroscopy (XPS) tests showed that the surfaces of Ni-Ti-Nb films were covered with Ti oxides, NiO and Nb2O5. The corrosion resistance of the Ni-Ti-Nb films in 3.5 wt.% NaCl solution was investigated using electrochemical tests such as open-circuit potential (OCP) and potentio-dynamic polarization tests. Ni-Ti-Nb films showed higher OCPs, higher corrosion potentials (Ecorr) and lower corrosion current densities (icorr) than the binary Ni-Ti film, which indicated a better corrosion resistance. The reason may be that Nb additions modified the passive layer on the film surface. The OCPs of Ni-Ti-Nb films increased with further Nb additions, whereas no apparent difference of Ecorr and icorr was found among the Ni-Ti-Nb films.
Original languageEnglish
Pages63 - 67
Volume414
Specialist publicationApplied Surface Science
PublisherElsevier B.V.
DOIs
Publication statusPublished - 31 Aug 2017

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Keywords

  • Ni-Ti-Nb; Thin film; Microstructures; Corrosion resistance

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