Fabrication of bioactive titania coating on nitinol by plasma electrolytic oxidation

H. T. Siu, Hau Chung Man

Research output: Journal article publicationJournal articleAcademic researchpeer-review

35 Citations (Scopus)

Abstract

Surface modification was attempted on Nitinol (NiTi) by plasma electrolytic oxidation (PEO) in aqueous solutions of sodium sulphate and sodium hydroxide (Na2SO4-NaOH) using an AC power supply. A thick and porous oxide layer with micron-sized pores was formed on the Nitinol substrate, with the thickness of the oxide layer ranging from a few μm to over 10 μm, depending on the processing time. X-ray diffraction (XRD) analysis confirmed that the oxide formed was anatase. Potentiodynamic polarization tests in Hanks' solution showed that the corrosion resistance of PEO-coated Nitinol was much higher than that of the substrate. More importantly, the apatite-forming ability of the PEO-treated NiTi was found to be enhanced. This could be attributed to the anatase crystalline structure of the titanium oxide and the porous structure that facilitates the anchorage of the hydroxyapatite particles.
Original languageEnglish
Pages (from-to)181-187
Number of pages7
JournalApplied Surface Science
Volume274
DOIs
Publication statusPublished - 1 Jun 2013

Keywords

  • Apatite
  • Corrosion
  • Nickel Titanium (NiTi)
  • Plasma Electrolytic Oxidation (PEO)
  • Titanium Oxide

ASJC Scopus subject areas

  • Surfaces, Coatings and Films

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