TY - JOUR
T1 - Irradiation creep of 3C-SiC and microstructural understanding of the underlying mechanisms
AU - Kondo, Sosuke
AU - Koyanagi, Takaaki
AU - Hinoki, Tatsuya
N1 - Funding Information:
This work was supported by JSPS KAKENHI Grant Number 24760715.
PY - 2014/5
Y1 - 2014/5
N2 - Irradiation-induced creep in high-purity silicon carbide was studied by an ion-irradiation method under various irradiation conditions. The tensioned surfaces of bent thin specimens were irradiated with 5.1 MeV Si2+ ions up to 3 dpa at 280-1200 °C, which is referred to as a single-ion experiment. Additional He+ ions were irradiated simultaneously in the dual-ion experiment to study the effects of transmuted helium on irradiation creep. Irradiation creep was observed above 400 °C in the single-ion case, where a linear relationship between irradiation creep and swelling (C/S) was observed at 400-800 °C for all stress levels (150, 225, and 300 MPa). The proportional constant of the C/S relationship was strongly dependent on temperature and stress. A rapid reduction in creep strain was observed above 1000 °C. On the basis of the microstructural analysis, anisotropic distribution of self-interstitial atom (SIA) clusters was suspected to be the primary creep mechanism. Some interesting results were obtained from re-irradiation under stress after the irradiation without stress. The creep strain was significantly retarded by pre-irradiation to even 0.01 dpa at 400 and 600 °C. This implies that the loop orientation was determined very early in the irradiation regime. For the dual-ion cases, irradiation creep was absent or very limited at all irradiation temperatures studied (400-800 °C). Microstructural analysis indicated that helium inhibited the stable growth of SIA clusters and prevented them from exhibiting anisotropic distribution.
AB - Irradiation-induced creep in high-purity silicon carbide was studied by an ion-irradiation method under various irradiation conditions. The tensioned surfaces of bent thin specimens were irradiated with 5.1 MeV Si2+ ions up to 3 dpa at 280-1200 °C, which is referred to as a single-ion experiment. Additional He+ ions were irradiated simultaneously in the dual-ion experiment to study the effects of transmuted helium on irradiation creep. Irradiation creep was observed above 400 °C in the single-ion case, where a linear relationship between irradiation creep and swelling (C/S) was observed at 400-800 °C for all stress levels (150, 225, and 300 MPa). The proportional constant of the C/S relationship was strongly dependent on temperature and stress. A rapid reduction in creep strain was observed above 1000 °C. On the basis of the microstructural analysis, anisotropic distribution of self-interstitial atom (SIA) clusters was suspected to be the primary creep mechanism. Some interesting results were obtained from re-irradiation under stress after the irradiation without stress. The creep strain was significantly retarded by pre-irradiation to even 0.01 dpa at 400 and 600 °C. This implies that the loop orientation was determined very early in the irradiation regime. For the dual-ion cases, irradiation creep was absent or very limited at all irradiation temperatures studied (400-800 °C). Microstructural analysis indicated that helium inhibited the stable growth of SIA clusters and prevented them from exhibiting anisotropic distribution.
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U2 - 10.1016/j.jnucmat.2013.09.004
DO - 10.1016/j.jnucmat.2013.09.004
M3 - Article
AN - SCOPUS:84899645428
VL - 448
SP - 487
EP - 496
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
SN - 0022-3115
IS - 1-3
ER -