603 Analysis of hydrogen behavior in some aluminum alloys by thermal desorption spectroscopy

The 6061 aluminum alloys are being used as a liner material of a high-pressure hydrogen tank for the fuel cell vehicles. However, it is known that some aluminum alloys cause hydrogen embrittlement. Therefore, it is important to confirm the location and amount of the hydrogen that exists inside the material. To conduct this, thermal desorption spectroscopy (TDS) is regarded as an effective examination method. It is thought hydrogen in the material is trapped by dislocations during processing, and that the dislocations that trap hydrogen move (glide) accompanying the hydrogen atoms in the material. However, the relationship between this kind of hydrogen behavior and the hydrogen embrittlement has not been clarified yet. Thus, in this study, the behavior of hydrogen affected by cold rolling was investigated by means of TDS on a 6061 aluminum alloy together with a pure (99.99%) aluminum. The amount of emitted hydrogen decreased significantly by the cold rolling both in the 6061 and pure aluminum, implying that hydrogen atoms that are trapped by the dislocations move in conjunction with dislocation gliding during the cold rolling.