TY - JOUR
T1 - Neutron Irradiation Induced Microstructural Changes in NBG-18 and IG-110 Nuclear Graphites
AU - Karthik, Chinnathambi
AU - Kane, Joshua
AU - Butt, Darryl P.
AU - Windes, William E.
AU - Ubic, Rick
N1 - Publisher Copyright:
© 2015 Elsevier Ltd. All rights reserved.
PY - 2015/5/1
Y1 - 2015/5/1
N2 - Abstract This paper reports the neutron-irradiation-induced effects on the microstructure of NBG-18 and IG-110 nuclear graphites. The high-temperature neutron irradiation at two different irradiation conditions was carried out at the Advanced Test Reactor National User Facility at the Idaho National Laboratory. NBG-18 samples were irradiated to 1.54 dpa and 6.78 dpa at 430 C and 678 C respectively. IG-110 samples were irradiated to 1.91 dpa and 6.70 dpa at 451 C and 674 C respectively. Bright-field transmission electron microscopy imaging was used to study the changes in different microstructural components such as filler particles, microcracks, binder and quinoline-insoluble (QI) particles. Significant changes have been observed in samples irradiated to about 6.7 dpa. The closing of pre-existing microcracks was observed in both the filler and the binder phases. The binder phase exhibited substantial densification with near complete elimination of the microcracks. The QI particles embedded in the binder phase exhibited a complete microstructural transformation from rosettes to highly crystalline solid spheres. The lattice images indicate the formation of edge dislocations as well as extended line defects bridging the adjacent basal planes. The positive climb of these dislocations has been identified as the main contributor to the irradiation-induced swelling of the graphite lattice.
AB - Abstract This paper reports the neutron-irradiation-induced effects on the microstructure of NBG-18 and IG-110 nuclear graphites. The high-temperature neutron irradiation at two different irradiation conditions was carried out at the Advanced Test Reactor National User Facility at the Idaho National Laboratory. NBG-18 samples were irradiated to 1.54 dpa and 6.78 dpa at 430 C and 678 C respectively. IG-110 samples were irradiated to 1.91 dpa and 6.70 dpa at 451 C and 674 C respectively. Bright-field transmission electron microscopy imaging was used to study the changes in different microstructural components such as filler particles, microcracks, binder and quinoline-insoluble (QI) particles. Significant changes have been observed in samples irradiated to about 6.7 dpa. The closing of pre-existing microcracks was observed in both the filler and the binder phases. The binder phase exhibited substantial densification with near complete elimination of the microcracks. The QI particles embedded in the binder phase exhibited a complete microstructural transformation from rosettes to highly crystalline solid spheres. The lattice images indicate the formation of edge dislocations as well as extended line defects bridging the adjacent basal planes. The positive climb of these dislocations has been identified as the main contributor to the irradiation-induced swelling of the graphite lattice.
UR - https://scholarworks.boisestate.edu/mse_facpubs/222
UR - https://doi.org/10.1016/j.carbon.2015.01.036
U2 - 10.1016/j.carbon.2015.01.036
DO - 10.1016/j.carbon.2015.01.036
M3 - Article
SN - 0008-6223
VL - 86
SP - 124
EP - 131
JO - Carbon
JF - Carbon
M1 - 9660
ER -