The Transport and Fate of Helium in Nanostructured Ferritic Alloys at Fusion Relevant He/DPA Ratios and DPA Rates
A novel in-situ 59Ni(n,α) reaction He-implanter technique is described, that was used to characterize the effect of the He/dpa ratio on microstructural evolution and changes in the flow properties of various materials at fusion relevant conditions. Irradiations in the High Flux Isotope reactor (HFIR) resulted in α-implantation from thin 1 to 5 µm NiAl coatings on TEM discs producing a uniform He concentration of 5 to 50 appm He/dpa to a depth of 5 to 8 μm. Initial post-irradiation TEM observations of MA957 irradiated to 9 dpa and 380 appm He at 500 ºC provide strong evidence for the existence of high density of small ≤ 1 nm size bubbles trapped on nano-scale YTiO clusters. In contrast, similar irradiations of Eurofer 97, described in a companion paper, produce a lower number density of larger cavities, which may be a mixture of bubbles and voids.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 917966
- Report Number(s):
- PNNL-SA-55263; AT6020100
- Journal Information:
- Journal of Nuclear Materials, 367-370:399-410, Journal Name: Journal of Nuclear Materials, 367-370:399-410
- Country of Publication:
- United States
- Language:
- English
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