NSUF 23-4768: Atom Probe Tomography and Transmission Electron Microscopy of Neutron-Irradiated Nanocrystalline Compositionally Complex Alloys
Despite interest in CCAs for nuclear applications, experimental data on neutron irradiation effects in CCAs has been rarely reported, and never at the in-service temperatures and high dose levels. Several RTEs awarded since 2022 focus on characterizing neutron-irradiated CCAs, with the aim of reducing this knowledge gap. RTE 22-4459 on the study of Cr10Fe30Mn30Ni30 irradiated at Idaho National Lab’s (INL’s) Advanced Test Reactor (ATR) analyzed samples irradiated up to 6 dpa at 395 and 579 ˚C and found chemical short-range ordering in samples at 579 ˚C but not at 395 ˚C. The recently-funded RTE 23-4521 will revisit these Cr10Fe30Mn30Ni30 samples and compare them to a precipitate-forming Al4Cr9Fe28Mn28Ni28Ti2 CCA under the same conditions to look at chemical redistribution and precipitation, as well as extended defect formation with compositional changes. This study proposes analysis of the microstructural evolution of two nanocrystalline Cr10Fe30Mn30Ni30 and Al4Cr9Fe28Mn28Ni28Ti2 CCA samples produced by high-pressure torsion (HPT) under the same neutron irradiation conditions. Many alloys have displayed a clear increase in radiation tolerance with reduced grain size due to the increased defect sink density, but the impact in precipitate-forming alloys and CCAs has not been investigated. The bulk irradiated materials from ATR will be characterized using the equipment at INL’s irradiated materials characterization lab (IMCL). Liftouts will be prepared from each sample using the FEI Quanta 3D FIB for TEM lamellae and APT tips. The FEI Titan S/TEM with superX-EDS will be used for observation of extended defects such as voids, dislocations, and chemical segregation/precipitation. The new 4D-STEM detector to be installed on the FEI Titan will also be used to analyze orientations of nano-precipitates in the neutron irradiated samples. Short range chemical ordering of the material will be observed using the Cameca LEAP 5000 Atom Probe and its high spatial resolution. This work would be completed within 9 months of the awarding of this proposal. This continuation of current neutron irradiated CCA work by highlighting the specific effect of grain size on irradiation response is extremely relevant to material design from both irradiation resistance and manufacturing perspectives. The influence of microstructural control during processing greatly impacts irradiation response, this work will be the first to explore this phenomenon within CCAs. With advanced reactor designs such as the lead-cooled fast reactor, molten salt reactor, and small modular reactors calling for advanced materials, this work directly supports the DOE-NE Advanced Reactor Concepts program.
Additional Info
| Field | Value |
|---|---|
| Abstract | Despite interest in CCAs for nuclear applications, experimental data on neutron irradiation effects in CCAs has been rarely reported, and never at the in-service temperatures and high dose levels. Several RTEs awarded since 2022 focus on characterizing neutron-irradiated CCAs, with the aim of reducing this knowledge gap. RTE 22-4459 on the study of Cr10Fe30Mn30Ni30 irradiated at Idaho National Lab’s (INL’s) Advanced Test Reactor (ATR) analyzed samples irradiated up to 6 dpa at 395 and 579 ˚C and found chemical short-range ordering in samples at 579 ˚C but not at 395 ˚C. The recently-funded RTE 23-4521 will revisit these Cr10Fe30Mn30Ni30 samples and compare them to a precipitate-forming Al4Cr9Fe28Mn28Ni28Ti2 CCA under the same conditions to look at chemical redistribution and precipitation, as well as extended defect formation with compositional changes. This study proposes analysis of the microstructural evolution of two nanocrystalline Cr10Fe30Mn30Ni30 and Al4Cr9Fe28Mn28Ni28Ti2 CCA samples produced by high-pressure torsion (HPT) under the same neutron irradiation conditions. Many alloys have displayed a clear increase in radiation tolerance with reduced grain size due to the increased defect sink density, but the impact in precipitate-forming alloys and CCAs has not been investigated. The bulk irradiated materials from ATR will be characterized using the equipment at INL’s irradiated materials characterization lab (IMCL). Liftouts will be prepared from each sample using the FEI Quanta 3D FIB for TEM lamellae and APT tips. The FEI Titan S/TEM with superX-EDS will be used for observation of extended defects such as voids, dislocations, and chemical segregation/precipitation. The new 4D-STEM detector to be installed on the FEI Titan will also be used to analyze orientations of nano-precipitates in the neutron irradiated samples. Short range chemical ordering of the material will be observed using the Cameca LEAP 5000 Atom Probe and its high spatial resolution. This work would be completed within 9 months of the awarding of this proposal. This continuation of current neutron irradiated CCA work by highlighting the specific effect of grain size on irradiation response is extremely relevant to material design from both irradiation resistance and manufacturing perspectives. The influence of microstructural control during processing greatly impacts irradiation response, this work will be the first to explore this phenomenon within CCAs. With advanced reactor designs such as the lead-cooled fast reactor, molten salt reactor, and small modular reactors calling for advanced materials, this work directly supports the DOE-NE Advanced Reactor Concepts program. |
| Award Announced Date | 2023-09-14T13:41:26.847 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Alina Zackrone |
| Irradiation Facility | None |
| PI | Nathan Curtis |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | None |