Hydrogen trapping behavior at vacancies introduced by electron irradiation in B2 ordered Fe base alloys

Abstract

We have investigated the hydrogen trapping behavior in B2 ordered Fe-50%Al alloy with electron irradiation followed by hydrogen implantation by using positron annihilation techniques, Xray diffraction and thermal desorption spectrometry (TDS). Positron annihilation lifetime and coincidence Doppler broadening measurement results showed that V Fe in B2 type Fe-Al alloys are dominantly introduced by low energy (2 MeV) electron irradiation, and more complex vacancy type defects are formed by high energy (8 MeV) electron irradiation. The result of TDS measurement showed that hydrogen atoms are trapped by vacancy type defects, the resulting hydrogen desorption behavior is different for 2 MeV and 8 MeV irradiation cases.