title: Hydrogen absorption of titanium and nickel-titanium alloys during long-term immersion in neutral fluoride solution.
abstract: Hydrogen absorption of biomedical titanium and Ni-Ti alloys in a neutral fluoride (2.0% NaF) solution for up to 10,000 h at 37 degrees C has been evaluated by means of hydrogen thermal desorption analysis. For alpha titanium (commercial pure titanium), the amount of absorbed hydrogen was, at most, 10-30 mass ppm, and the corrosion product and hydride formation were revealed on the surface of the specimen by X-ray diffraction analysis. Ni-Ti superelastic alloy absorbed approximately 150 mass ppm of hydrogen, which was probably sufficient to result in the pronounced degradation of the mechanical properties, although corrosion was hardly observed. In contrast, hydrogen absorption of alpha-beta titanium (Ti-6Al-4V) and beta titanium (Ti-11.3Mo-6.6Zr-4.3Sn) alloys was negligible, although general corrosion was observed. The results of the present study indicate that the susceptibility of titanium and Ni-Ti alloys to hydrogen absorption in the neutral fluoride solution is different from that in the acidic fluoride solution reported previously.
authors.affiliation: Department of Biomaterials and Bioengineering, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8504, Japan. yokken@dent.tokushima-u.ac.jp
authors.forename: Ken'ichi
authors.initials: K
authors.lastname: Yokoyama
authors.forename: Toshio
authors.initials: T
authors.lastname: Ogawa
authors.forename: Kenzo
authors.initials: K
authors.lastname: Asaoka
authors.forename: Jun'ichi
authors.initials: J
authors.lastname: Sakai
mesh_terms: D001672:Biocompatible Materials; D005459:Fluorides; D006859:Hydrogen; D009532:Nickel; D014025:Titanium
chemical_list: D001672:Biocompatible Materials; C040654:titanium nickelide; D009532:Nickel; D006859:Hydrogen; D014025:Titanium; D005459:Fluorides