Internal friction study of ambient aging behaviors of irradiated tungsten by Si/H ions

The aging behaviors of irradiated tungsten by high energy Si3+ and H+ ions are mainly investigated using internal friction (IF) method combined with SEM technology. The SEM analysis indicates that more severe irradiation damage appears in the surface of simultaneous dual Si3+ + H+ irradiated specimen than that in the sequential dual Si3+ + H+ irradiated specimen or the single Si3+ irradiated specimens because of the synergistic effect of Si and H irradiation. The IF background of the irradiated sample is about one order of magnitude higher than that of the unirradiated sample owing to the existence of high density fresh dislocations induced by Si/H irradiation. In the sequential dual Si3+ and H+ irradiated specimen, the hydrogen Snoek-Ke-Koster (SKK) peak associated with the movement of dislocations dragging hydrogen atoms is observed and its height decreases with aging time at room temperature. As for the simultaneous dual Si3+ + H+ irradiated specimen, however, there is no such hydrogen SKK peak. The reason can be explained as hydrogen diffusion and pinning effect of dislocations.