軽金属
Online ISSN : 1880-8018
Print ISSN : 0451-5994
ISSN-L : 0451-5994
66 巻, 2 号
選択された号の論文の8件中1~8を表示しています
技術報告
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研究論文
  • 堀川 敬太郎, 外薗 俊輔, 小林 秀敏
    原稿種別: 研究論文
    2016 年 66 巻 2 号 p. 77-83
    発行日: 2016/02/28
    公開日: 2016/03/30
    ジャーナル フリー
    A testing apparatus, which can simultaneously monitor the hydrogen gas release and the progress of fracture, was newly developed in order to clarify the behavior of hydrogen atoms on hydrogen embrittlement in aluminum alloys. This apparatus is composed of a tensile testing machine equipped with two mass spectrometers and a high-speed microscope placed in an ultrahigh vacuum (UHV) chamber. By using this apparatus, we have succeeded in detecting hydrogen (deuterium) gas evolution dynamically during grain boundary fracture in a 7075 aluminum alloy indicating hydrogen embrittlement. Concentration of hydrogen atoms at the grain boundary associated with hydrogen embrittlement was estimated to be more than 3.0×10−7 mol/m2. It was also clarified that deuterium atoms introduced from the testing atmosphere were released not only at the moment of fracture but also at the plastic deformation.
  • 堀川 敬太郎, 高橋 優花, 小林 秀敏
    原稿種別: 研究論文
    2016 年 66 巻 2 号 p. 84-89
    発行日: 2016/02/28
    公開日: 2016/03/30
    ジャーナル フリー
    Hydrogen microprint technique (HMT) was repeatedly applied to Al–Mg–Si base alloys without and with containing iron as an impurity element. A special jig was made to perform the repeated HMT, which can keep a constant loading using one specimen. By using this testing jig, we could verify the hydrogen emission behavior in the same microstructure of the Al–Mg–Si base alloys during deformation. It was shown that hydrogen atoms were released at grain boundaries in the early stage of the plastic deformation. When the applied strain was then increased, hydrogen atoms were released at the periphery of iron based intermetallic inclusions. Based on this, it was believed that hydrogen-trapping force by the inclusions was higher than that by grain boundary during deformation.
  • 堀川 敬太郎, 小椋 智, 宮川 唯, 遠藤 剛, 高橋 誠, 小林 秀敏
    原稿種別: 研究論文
    2016 年 66 巻 2 号 p. 90-95
    発行日: 2016/02/28
    公開日: 2016/03/30
    ジャーナル フリー
    Hydrogen desorption behavior in 6061 and 7075 aluminum alloys was studied by means of thermal desorption analysis using a semiconductor hydrogen sensor in the gas chromatograph. Effect of high strain rate deformation (105 s−1) on the hydrogen trapping state in the alloys was examined in particular. It was found that hydrogen atoms were released at lower temperatures when both alloys were plastically deformed. The tendency was more obvious in the 6061 alloys deformed with a high strain rate. In comparison with the previous reports, the difference of the hydrogen desorption behavior in the case between high speed and low speed deformation would be related to the difference of the hydrogen trapping effects by the different type of lattice defects.
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