title: Fracture associated with hydrogen absorption of sustained tensile-loaded titanium in acid and neutral fluoride solutions.
abstract: The fracture of commercial pure titanium in acid and neutral fluoride solutions has been examined by a sustained tensile-loading test and hydrogen thermal desorption analysis. It was found that the fracture of titanium occurred in neutral 2.0% NaF solution as well as in 2.0% acidulated phosphate fluoride (APF) solution. The time to fracture decreased with increasing applied stress in both 2.0% APF and 2.0% NaF solutions. In the case of the same applied stress, the time to fracture in the 2.0% APF solution was shorter than that in the 2.0% NaF solution. General corrosion was exhibited on the side surface of the tested specimens. The formation of sodium titanium fluoride was observed on the surface of the immersed specimens in the 2.0% APF solution. Hydrogen desorption of the tested specimen in the 2.0% APF solution was observed with a peak at approximately 600 degrees C. The amount of absorbed hydrogen was >300 mass ppm in the 2.0% APF solution under an applied stress for 24 h. The results of the present study imply that applying stress to titanium by immersing in fluoride solutions leads to the degradation of its mechanical properties.
authors.affiliation: Department of Dental Engineering, School of Dentistry, The University of Tokushima, 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: Kazuyuki
authors.initials: K
authors.lastname: Kaneko
authors.forename: Youji
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: Kenzo
authors.initials: K
authors.lastname: Asaoka
authors.forename: Jun'ichi
authors.initials: J
authors.lastname: Sakai
authors.forename: Michihiko
authors.initials: M
authors.lastname: Nagumo
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D001697:Biomedical and Dental Materials; D005459:Fluorides / Q000737:chemistry*; D006859:Hydrogen; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D013314:Stress, Mechanical; D013718:Tensile Strength; D013816:Thermodynamics; D014025:Titanium / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D001697:Biomedical and Dental Materials; D006859:Hydrogen; D014025:Titanium; D005459:Fluorides