NSUF 16-656: TEM in situ microcantilever testing of irradiated F/M alloys
The objective of this project is to acquire a multiscale mechanistic understanding of grain boundary cohesion and fracture in irradiated ferritic/martensitic (F/M) alloys, through transmission electron microscopic (TEM) in situ cantilever testing. F/M steels are candidates for cladding and structural components of advanced nuclear reactors. It is well known, however, that these materials exhibit grain boundary radiation-induced segregation (RIS) of Cr and minor alloying elements. RIS changes the grain boundary cohesive energy, which consequently affects the fracture behavior of the material. This is an inherently multiscale problem, as RIS is a point defect-driven process, grain boundary cohesion a microscale challenge, and fracture a macroscopic consequence. Previously, RIS and fracture experiments had to be conducted ex situ. Now, TEM mechanical testing enables in situ testing of RIS, crack propagation, and fracture. Thus, we hypothesize that TEM in situ microcantilever tests are the ideal tool for understanding fracture mechanisms across the length scales. In this work, we propose to conduct TEM in situ microcantilever tests of three irradiated commercial F/M alloys T91, HCM12A, and HT9. We will observe and record video of crack propagation. Grain boundary RIS measurements will connect the cracking to atomistic models of grain boundary chemistry and cohesion. Microcantilever tests will also generate load-displacement-time data that can be used to calculate cohesive laws governing macroscopic fracture. In summation, this experimental approach will link atomic, micro, and macro length scales, providing tremendous insight into the mechanisms governing fracture of irradiated F/M alloys. This work will also provide validation for finite element models in MOOSE.
Información adicional
| Campo | Valor |
|---|---|
| Awarded Institution | Boise State University |
| Embargo End Date | 2018-01-11 |
| Facility Tech Lead | Adrien Couet, Alex Long, Alina Montrose, Kory Linton, Mukesh Bachhav, Thomas Hartman |
| NSUF Call | FY 2016 RTE 2nd Call |
| PI | Janelle Wharry |
| Project Member | Professor Janelle Wharry, Professor - University of Illinois (https://orcid.org/0000-0001-7791-4394) |
| Project Member | Dr. Kayla Yano, Materials Scientist - Pacific Northwest National Laboratory (https://orcid.org/0000-0002-8182-5439) |
| Project Type | RTE |
| Publication | In situ TEM fracture testing for shallow ion irradiated layers Janelle Wharry, Kayla Yano Microscopy & Microanalysis 2017 2017-04-06 - 2017-01-07 |
| Publication | In situ TEM mechanical testing: an emerging approach for characterization of polycrystalline, irradiated alloys Matthew Swenson, Janelle Wharry, Yaqiao Wu, Kayla Yano Microscopy & Microanalysis 2016-07-24 - 2016-07-28 |
| Publication | In situ TEM microcompression pillar size effects in Fe-9Cr ODS Matthew Swenson, Janelle Wharry, Kayla Yano American Nuclear Society 2016-06-12 - 2016-06-16 |
| Publication | Correlation between irradiation defects and transition dimension for TEM in situ mechanical testing Matthew Swenson, Janelle Wharry, Kayla Yano American Nuclear Society 2017 Annual Meeting 2018-06-11 - 2018-06-15 |
| Publication | Intrinsic-extrinsic size effect relationship for micromechanical tests Janelle Wharry, Kayla Yano, Priyam Patki Scripta Materialia 162 2019-03-01 https://doi.org/10.1016/j.scriptamat.2018.10.045 |
| Publication | Understanding plasticity in irradiated alloys through TEM in situ compression pillar tests Kayla Yano, Priyam Patki, Matthew Swenson Journal of Materials Research 35 2020-04-01 https://www.cambridge.org/core/journals/journal-of-materials-research/article/understanding-plasticity-in-irradiated-alloys-through-tem-in-situ-compression-pillar-tests/BC4E6C260679C6B6B772D0E5F7A90B1B |
| Publication | Understanding plasticity in irradiated alloys through TEM in situ compression pillar tests Janelle Wharry, Haozheng Qu, Kayla Yano, Priyam Patki, Matthew Swenson Journal of Materials Research 35 2020-05-01 http://doi.org/10.1557/jmr.2019.295 |
| RTE Number | 656 |