NSUF 25-5434: Examining Mechanical Performance of Alloy T91 To High DPA using Nanoindentation

We propose to characterize the changes in mechanical properties in T91 measured through microhardness and nanohardness testing after high dose irradiation in the Fast Flux Test Facility and BOR-60. In addition to irradiations conducted on alloy T91 in the BOR-60 reactor up to 81 dpa in a range from about 376°C to 525°C, the same heat of alloy T91 was irradiated in the historical Fast Flux Test Facility (FFTF) in the Materials Open Test Assembly (MOTA) experiments at similar temperatures up to 184 dpa. The team seeks, through NSUF, to examine the mechanical performance of the same steel irradiated in two fast reactors under similar conditions using Vickers hardness and instrumented indentation testing (nanoindentation). We hypothesize that by understanding microstructure-mechanical property relationships between three radiation environments, the properties can be extrapolated using multiple datasets to form a comprehensive curve, and thus accelerate materials evaluation for advanced nuclear technologies.

Additional Info

Field	Value
Awarded Institution	Pacific Northwest National Laboratory
DOI	10.46936/NSUF/60015384
Embargo End Date	2027-09-03
Facility Tech Lead	Kory Linton, Stuart Maloy
NSUF Call	FY 2025 RTE 2nd Call
PI	Stuart Maloy
PIE Facilities	Low Activation Materials Design and Analysis Laboratory
Prep Facilities	Materials Science and Technology Laboratory
Project Member	Dr. Stuart Maloy, Senior Nuclear Materials Adviser - Pacific Northwest National Laboratory (https://orcid.org/0000-0001-8037-1319)
Project Member	Dr. Stephen Taller, R&D Staff Scientist - Oak Ridge National Laboratory (https://orcid.org/0000-0002-7323-4786)
Project Member	Mr. Ramprashad Prabhakaran, Scientist - Pacific Northwest National Laboratory (https://orcid.org/0000-0002-8117-2677)
Project Member	Dr. Steven Zinkle, Professor - University of Tennessee-Knoxville (https://orcid.org/0000-0003-2890-6915)
Project Type	RTE