Abstract
Samples of aluminum alloy 6061 produced via ultrasonic additive manufacturing (UAM) were irradiated in the High Flux Isotope Reactor (HFIR) up to 17.3 dpa at ~70°C while in contact with water using perforated rabbit capsules. The irradiation campaign included as-received (AR) material, specimens subjected to various post-weld heat treatments (PWHTs, including hot isostatic pressing [HIP]), and reference (wrought) alloy samples. Mechanical tensile tests, accompanied by digital image correlation (DIC) analysis, fractography, and metallography, were performed as a part of the post-irradiation evaluation. The X- and Y-specimens (i.e., oriented in the sonotrode moving and vibration directions, respectively) showed pronounced radiation hardening and ductility decrease. Specific serration flow behavior and propagation of deformation bands were observed under various material conditions up to 3.5 dpa but disappeared at 17.3 dpa. In all cases, the fracture mechanism of X- and Y-specimens was ductile; ductile dimples dominated the fracture surface. Irradiated X- and Y-specimens showed good performance, regardless of material conditions (AR or PWHT). The performance of Z-specimens oriented in the build direction was strongly dependent on the PWHT. The AR and aged specimens showed fracture stress decrease with dose, and they experienced fracture under irradiation after 3.5 dpa; specimen cross section analysis revealed specific interface degradation that was likely related to corrosion. Recrystallization significantly improved in-reactor performance. HIP suppressed interface degradation due to recrystallization and pore removal, which led to good in-reactor performance for Z-specimens.
| Original language | English |
|---|---|
| Article number | 152939 |
| Journal | Journal of Nuclear Materials |
| Volume | 550 |
| DOIs | |
| State | Published - Jul 2021 |
Funding
The authors would like to thank Daniel Pinkston, Chris Bryan, T.S. Byun, and David McClintock at Oak Ridge National Laboratory (ORNL) for useful discussions and review of the work. The help and support of ORNL's Irradiated Materials Examination and Testing Facility (IMET) staff (manager: Mark Delph) and the Low-Activation Materials Design and Analysis Laboratory (LAMDA) staff (manager: J. Schmidlin) are gratefully acknowledged. The authors also would like to thank Mark Norfolk and Adam Hehr at Fabrisonic, LLC, for UAM manufacturing support. This research was supported by Laboratory Directed Research and Development (LDRD) Program funds at ORNL (LOIS 7345). A portion of this research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by ORNL. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy(DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE 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 ).
| Funders | Funder number |
|---|---|
| U.S. Department of Energy | |
| Office of Science | |
| Oak Ridge National Laboratory | LOIS 7345 |
| Laboratory Directed Research and Development |
Keywords
- DIC
- HFIR
- Ultrasonic additive manufacturing
- hot isostatic pressing
- neutron irradiation
- post-weld heat treatment
- tensile tests
