Abstract
The microstructure, trapped transmutation gases, stored energy, and mechanical behavior of samples from an irradiated Inconel 718 proton beam window were characterized using transmission electron microcopy, thermal desorption spectrometry (TDS), differential scanning calorimetry (DSC), and tensile testing. In the as-irradiated condition the microstructure contained a high number density of 1–3 nm gas-filled nanocavities. Emissions of trapped gases, H and He, during TDS correlated with peaks of the energy release curves from DSC examinations, which suggest these gases were likely stored in highly stable defect traps. The stored energy from radiation damage saturated at doses of a few dpa and did not increase with increasing radiation dose, but the amount of stored H and He increased with increasing dose. Effects of post-irradiation annealing were studied as well. After exposure to 700 °C, the nanocavities grew only slightly to 2–4 nm in diameter, but after exposure to 900 °C, the cavities grew to 10–20 nm in diameter and electron energy-loss spectroscopy showed these cavities contained a core of He surrounded by a shell of H. This study demonstrated that the irradiation defect structures containing H and He were remarkably stable during irradiation and after exposure up to 700 °C. The effect of the irradiation temperature, defect mobility, and interaction of H, He, and irradiation defects on mechanical behavior provides insight into the processes responsible for the unusual recovery in ductility with increasing radiation dose observed in Inconel 718 after high energy proton and spallation neutron irradiation.
| Original language | English |
|---|---|
| Article number | 148111 |
| Journal | Materials Science and Engineering: A |
| Volume | 929 |
| DOIs | |
| State | Published - May 2025 |
Funding
Notice: This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).The assistance, technical insights, and discussion with Dr. Jordan Hachtel at ORNL, Dr. Charles Hirst at the University of Michigan, and Dr. Frank Garner at Radiation Effects Consulting are gratefully acknowledged. The efforts of the remote handling team at the Spallation Neutron Source and the staff at the Low Activation Materials Design and Analysis Laboratory are gratefully acknowledged, especially Travis Dixon, Patty Tedder, Kyle Everett, and Stephanie Curlin. This work was supported by the Post-Irradiation Examination program at the Spallation Neutron Source. The SNS is sponsored by the Office of Science, US Department of Energy, and managed by UT-Battelle, LLC for the US Department of Energy under Contract DE-AC05-00OR22725. Scanning transmission electron microscopy-electron energy loss spectroscopy was performed using the instruments as part of a user proposal at the Center for Nanophase Materials Sciences, a DOE Office of Science User Facility operated by ORNL. Notice: This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). The assistance, technical insights, and discussion with Dr. Jordan Hachtel at ORNL, Dr. Charles Hirst at the University of Michigan, and Dr. Frank Garner at Radiation Effects Consulting are gratefully acknowledged. The efforts of the remote handling team at the Spallation Neutron Source and the staff at the Low Activation Materials Design and Analysis Laboratory are gratefully acknowledged, especially Travis Dixon, Patty Tedder, Kyle Everett, and Stephanie Curlin. This work was supported by the Post-Irradiation Examination program at the Spallation Neutron Source. The SNS is sponsored by the Office of Science, US Department of Energy, and managed by UT-Battelle, LLC for the US Department of Energy under Contract DE-AC05-00OR22725. Scanning transmission electron microscopy-electron energy loss spectroscopy was performed using the instruments as part of a user proposal at the Center for Nanophase Materials Sciences, a DOE Office of Science User Facility operated by ORNL.
Keywords
- Electron microscopy
- Inconel 718
- Nanocavities
- Radiation effects
- Stored energy
- Transmutation gases