Abstract
Post–neutron irradiation examination is performed on advanced accident-tolerant fuel (ATF) cladding iron-chromium-aluminum (FeCrAl) alloys with ∼10–13at. % Cr, ∼10–12 at. % Al, ∼1 at. % Mo, and minor alloying elements including Y irradiated to a damage level of 7 displacements per atom (dpa) at irradiation temperatures of 267–282 °C. A compositional dependency of the Cr and Al content is observed on the ratio of sessile and glissile dislocation loops, where the density of a⟨100⟩ type loops is somewhat higher than the a/2⟨111⟩ type loops. The α′ precipitate number density is inversely correlated to the starting Cr concentration of the alloys of interest. The irradiation to a higher dose of 7 dpa results in a higher density of dislocation loops and α′ precipitates for the same alloys at a lower irradiation dose, such as 1.8 dpa. In this work, the effect of α′ precipitates on the dislocation loop density is discussed, and the presence of α′ appears to inhibit the nucleation of loops. Compared with first-generation FeCrAl alloys, these advanced alloys with heterogeneous structure exhibit a lower Cr concentration in α′ precipitation at the same dose level; they act as weaker obstacles deviating from the primary hardening contribution from the mature α′. Hence, the overall irradiation-induced hardening decreases; our alloys show improved radiation resistance because of their stronger sink strengths. The results presented in this paper could provide insights for the design and optimization of ATF cladding materials for future fission and space applications.
| Original language | English |
|---|---|
| Article number | 117843 |
| Journal | Acta Materialia |
| Volume | 231 |
| DOIs | |
| State | Published - Jun 1 2022 |
Funding
Research was sponsored by the DOE Office of Nuclear Energy, Advanced Fuel Campaign (AFC) of the Nuclear Technology R&D program under contract DE-AC05–00OR22725. Neutron irradiation of FeCrAl alloys at ORNL's HFIR user facility was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, DOE. A portion of this research was conducted at ORNL's Center for Nanophase Materials Sciences (CNMS), which is a DOE Office of Science User Facility. This research was performed, in part, using instrumentation (FEI Talos) provided by the Department of Energy (DOE), Office of Nuclear Energy, Fuel Cycle R&D Program, and the Nuclear Science User Facilities (NSUF). A portion of this work was funded by a NSUF Rapid Turnaround Experiment (RTE) and was conducted at the Center for Advanced Energy Studies (CAES)–Microscopy and Characterization Suite (MaCS). The authors would like to thank Yaqiao Wu, Jatu Burns, and Megha Dubey for assistance with completing the RTE. Authors would like to thank Dr T.S. Byun (ORNL), Dr. W. Zhong, (ORNL), Mr. G.E. Mattingly (ORNL), Mr. J.W. Werden (ORNL), Ms. A.G. Le Coq (ORNL), Mr. K.D. Linton (ORNL) and Dr. P.V. Patki (University of Michigan) for discussing the results, providing fruitful comments, and reviewing the paper; staff of the Irradiated Materials Examination and Testing facility and LAMDA (Low Activation Materials Design and Analysis Laboratory) for sample transfer and preparation as well as their continuing support. Research was sponsored by the DOE Office of Nuclear Energy, Advanced Fuel Campaign (AFC) of the Nuclear Technology R&D program under contract DE-AC05–00OR22725. Neutron irradiation of FeCrAl alloys at ORNL's HFIR user facility was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, DOE. A portion of this research was conducted at ORNL's Center for Nanophase Materials Sciences (CNMS), which is a DOE Office of Science User Facility. This research was performed, in part, using instrumentation (FEI Talos) provided by the Department of Energy (DOE), Office of Nuclear Energy, Fuel Cycle R&D Program, and the Nuclear Science User Facilities (NSUF). A portion of this work was funded by a NSUF Rapid Turnaround Experiment (RTE) and was conducted at the Center for Advanced Energy Studies (CAES)–Microscopy and Characterization Suite (MaCS). The authors would like to thank Yaqiao Wu, Jatu Burns, and Megha Dubey for assistance with completing the RTE. Authors would like to thank Dr T.S. Byun (ORNL), Dr. W. Zhong, (ORNL), Mr. G.E. Mattingly (ORNL), Mr. J.W. Werden (ORNL), Ms. A.G. Le Coq (ORNL), Mr. K.D. Linton (ORNL) and Dr. P.V. Patki (University of Michigan) for discussing the results, providing fruitful comments, and reviewing the paper; staff of the Irradiated Materials Examination and Testing facility and LAMDA (Low Activation Materials Design and Analysis Laboratory) for sample transfer and preparation as well as their continuing support.
| Funders | Funder number |
|---|---|
| Advanced Fuel Campaign | DE-AC05–00OR22725 |
| Scientific User Facilities Division | |
| U.S. Department of Energy | |
| Office of Science | |
| Office of Nuclear Energy | |
| Basic Energy Sciences | |
| Oak Ridge National Laboratory | |
| University of Michigan |
Keywords
- Accident tolerant
- Dislocation loops
- Ferritic steels
- Irradiation
- Precipitation