Delayed fracture of beta titanium orthodontic wire in fluoride aqueous solutions

Kazuyuki Kaneko, Ken'ichi Yokoyama*, Keiji Moriyama, Kenzo Asaoka, Jun'ichi Sakai, Michihiko Nagumo


    研究成果: Article査読

    89 被引用数 (Scopus)


    Hydrogen embrittlement of a beta titanium orthodontic wire has been examined by means of a delayed-fracture test in acid and neutral fluoride aqueous solutions and hydrogen thermal desorption analysis. The time to fracture increased with decreasing applied stress in 2.0% and 0.2% acidulated phosphate fluoride (APF) solutions. The fracture mode changed from ductile to brittle when the applied stress was lower than 500MPa in 2.0% APF solution. On the other hand, the delayed fracture did not occur within 1000h in neutral NaF solutions, although general corrosion was also observed similar to that in APF solutions. Hydrogen desorption of the delayed-fracture-tested specimens was observed with a peak at approximately 500°C. The amount of absorbed hydrogen was 5000-6500 mass ppm under an applied stress in 2.0% APF solution for 24h. It is concluded that the immersion in fluoride solutions leads to the degradation of the mechanical properties and fracture of beta titanium alloy associated with hydrogen absorption.

    出版ステータスPublished - 2003 5月

    ASJC Scopus subject areas

    • バイオテクノロジー
    • バイオエンジニアリング
    • 生体医工学


    「Delayed fracture of beta titanium orthodontic wire in fluoride aqueous solutions」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。