NSUF 17-923: a' precipitation in neutron-irradiated Fe-9/12Cr alloys
High chromium ferritic/martensitic (F-M) steels are one of the strong contenders for structural components of the next generation of nuclear reactors and future fusion reactors. The long-term use of these steels in intense neutron irradiation environments requires reliable predictions of the evolution of their microstructures and mechanical properties. Developing accurate models that can predict phase transformations, accelerated diffusion, and other irradiation-affected phenomena, requires experimental insight and validation. Previous work has shown that nanoscale a’ precipitates readily form in neutron irradiated Fe-Cr. However a number of outstanding questions remain concerning the effects of temperature. Therefore the proposed work will focus on nucleation mechanisms, synergy with developing dislocation loops, and growth of a’ precipitates, Using transmission electron microscopy and atom probe tomography, we will characterize the Fe-9Cr and Fe-12Cr model alloys that were irradiated at Bor-60 under conditions spanning a larger temperature range than previously studied.
In combination with parallel experimental efforts focusing on a’ precipitation in ion implanted FeCr alloys, careful comparison of the different microstructural features formed under ion irradiation and neutron irradiation will provide a unique understanding of the evolution of irradiated microstructures as a first step toward tailoring ion irradiations to achieve optimum emulation of the reactor irradiated microstructure for specific neutron spectra.
Samples are at Oak Ridge National Laboratory are in the process of being transferred to the LAMDA facility where the focused ion beam (FIB) instrument will be used to prepare transmission electron microscopy (TEM) samples that will be examined on the LAMDA TEM instrument. The FIB tool will also be used to initiate the preparation of atom probe tomography samples that will be shipped to the University of Michigan for final preparation and complete APT analysis. Samples will start becoming available by mid February 2017. The proposed work will take 6 months.
Additional Info
| Field | Value |
|---|---|
| Abstract | High chromium ferritic/martensitic (F-M) steels are one of the strong contenders for structural components of the next generation of nuclear reactors and future fusion reactors. The long-term use of these steels in intense neutron irradiation environments requires reliable predictions of the evolution of their microstructures and mechanical properties. Developing accurate models that can predict phase transformations, accelerated diffusion, and other irradiation-affected phenomena, requires experimental insight and validation. Previous work has shown that nanoscale a’ precipitates readily form in neutron irradiated Fe-Cr. However a number of outstanding questions remain concerning the effects of temperature. Therefore the proposed work will focus on nucleation mechanisms, synergy with developing dislocation loops, and growth of a’ precipitates, Using transmission electron microscopy and atom probe tomography, we will characterize the Fe-9Cr and Fe-12Cr model alloys that were irradiated at Bor-60 under conditions spanning a larger temperature range than previously studied. In combination with parallel experimental efforts focusing on a’ precipitation in ion implanted FeCr alloys, careful comparison of the different microstructural features formed under ion irradiation and neutron irradiation will provide a unique understanding of the evolution of irradiated microstructures as a first step toward tailoring ion irradiations to achieve optimum emulation of the reactor irradiated microstructure for specific neutron spectra. Samples are at Oak Ridge National Laboratory are in the process of being transferred to the LAMDA facility where the focused ion beam (FIB) instrument will be used to prepare transmission electron microscopy (TEM) samples that will be examined on the LAMDA TEM instrument. The FIB tool will also be used to initiate the preparation of atom probe tomography samples that will be shipped to the University of Michigan for final preparation and complete APT analysis. Samples will start becoming available by mid February 2017. The proposed work will take 6 months. |
| Award Announced Date | 2017-04-26T10:05:31.26 |
| Awarded Institution | University of Wisconsin |
| Facility | University of Wisconsin Ion Beam Laboratory |
| Facility Tech Lead | Kory Linton, Kumar Sridharan |
| Irradiation Facility | None |
| PI | Emmanuelle Marquis |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 923 |