title: Inhibition of hydrogen embrittlement of Ni-Ti superelastic alloy in acid fluoride solution by hydrogen peroxide addition.
abstract: Inhibition of the hydrogen embrittlement of Ni-Ti superelastic alloy in an acidulated phosphate fluoride (APF) solution has been attempted by adding various amounts of H(2)O(2). In a 0.2% APF solution, hydrogen absorption is markedly inhibited by adding H(2)O(2), although corrosion is slightly enhanced by increasing the amount of added H(2)O(2). By adding a small amount of H(2)O(2) (0.001 M), in the early stage of immersion, hydrogen embrittlement is inhibited and corrosion is only slightly enhanced. Upon adding H(2)O(2), it appears that the dominant cathodic reactions change from hydrogen evolution to H(2)O(2) reduction reactions, or the surface conditions of the alloy are changed by H(2)O(2) with a high oxidation capability, thereby inhibiting hydrogen absorption. The present study clearly indicates that infinitesimal addition of H(2)O(2) into acid fluoride solutions is effective for the inhibition of the hydrogen embrittlement of the alloy.
authors.affiliation: Department of Materials Science and Engineering, Kyushu Institute of Technology, Tobata-ku, Kitakyushu, Japan. yokken@post.matsc.kyutech.ac.jp
authors.forename: Ken'ichi
authors.initials: K
authors.lastname: Yokoyama
authors.forename: Yushin
authors.initials: Y
authors.lastname: Yazaki
authors.forename: Jun'ichi
authors.initials: J
authors.lastname: Sakai
mesh_terms: D000042:Absorption; D000149:Acidulated Phosphate Fluoride / Q000737:chemistry*; D000497:Alloys / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D009969:Orthodontic Wires; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; C040654:titanium nickelide; D000149:Acidulated Phosphate Fluoride; D009532:Nickel; D006859:Hydrogen; D006861:Hydrogen Peroxide; D014025:Titanium