NSUF 16-865: Ion irradiation of advanced materials – nanostructured steels and high entropy alloysNew Proposal
Efforts are undergoing to extend the life of current reactors and develop advanced reactors, which requires nuclear materials with improved properties (e.g., irradiation tolerance, mechanical properties, and corrosion resistance). However, currently used materials sometimes cannot meet the demanding requirements, and life extension of current reactors and development of advanced reactors can be limited by materials. Hence, it is very important to develop and evaluate new materials for potential application in nuclear reactors. Nanostructured steels possess dramatically higher strength than their conventional coarse-grained (CG) counterparts, owing to significant grain boundary strengthening, and have significantly enhanced irradiation tolerance due to significant volume fraction of grain boundaries that serve as sinks or recombination centers for radiation-induced defects. However, there has been very limited studies on irradiation of nanostructured steels, and their performance under irradiation at relevant reactor operating temperatures remains unclear. HEAs are a new class of materials that contain multiple principal elements in almost equal proportions and have random solid-solution phases with simple crystal structures. HEAs possess significantly improved mechanical properties over conventional alloys, such as high strength-weight ratio, fracture resistance, high-temperature strength and structural stability. Furthermore, HEAs have been proposed to possess significantly enhanced irradiation tolerance. The inherent disorder (or random arrangement of different elements) could mitigate damage by annihilating Frenkel pairs at early stages of cascade events. However, radiation damage studies of HEAs are extremely limited. This proposed work will systematically study the irradiation performance of nanostructured steels and HEAs, assess their potential applications in LWRs and advanced fast reactors as structural materials or fuel cladding, and establish/enhance our fundamental understanding of irradiation effects in these materials. The establishment of irradiation performance of novel advanced materials with appealing properties will impact the life extension of current reactors and the development of advanced reactors. The project will use ion irradiation to mimic neutron irradiation. Note that this project will only include ion irradiation due to the large number of sample sets involved, and detailed post-irradiation examination will be proposed in future proposals. The project will include 6 sets of samples: (1) CG 304 steel; (2) UFG 304 steel; (3) NC 304 steel; (4) UFG FeCrNiCo HEA; (5) UFG FeCrNiCoMn HEA; (6) UFG Fe30Ni30Co30Mn10 HEA. CG steels provide a baseline for comparison to UFG and NC steels. Irradiation behavior of the three HEAs with different compositions will be compared to study the effect of composition on irradiation tolerance. We fully recognize that Co is present in the HEAs to be studied and that Co element is not suitable for nuclear application due to long-term activation issues, however, they are used for this project to demonstrate the concept of enhanced irradiation tolerance of HEAs. All 6 sample sets will be irradiated in the Ion Beam Laboratory at University of Wisconsin - Madison. Two irradiation conditions will be utilized for each sample set: 300 oC, 50 dpa; 500 oC, 50 dpa. Fe +2 ion will be used for the ion irradiation. The expected period of performance of the project is Jan. – Feb. 2017.
Additional Info
| Field | Value |
|---|---|
| Abstract | Efforts are undergoing to extend the life of current reactors and develop advanced reactors, which requires nuclear materials with improved properties (e.g., irradiation tolerance, mechanical properties, and corrosion resistance). However, currently used materials sometimes cannot meet the demanding requirements, and life extension of current reactors and development of advanced reactors can be limited by materials. Hence, it is very important to develop and evaluate new materials for potential application in nuclear reactors. Nanostructured steels possess dramatically higher strength than their conventional coarse-grained (CG) counterparts, owing to significant grain boundary strengthening, and have significantly enhanced irradiation tolerance due to significant volume fraction of grain boundaries that serve as sinks or recombination centers for radiation-induced defects. However, there has been very limited studies on irradiation of nanostructured steels, and their performance under irradiation at relevant reactor operating temperatures remains unclear. HEAs are a new class of materials that contain multiple principal elements in almost equal proportions and have random solid-solution phases with simple crystal structures. HEAs possess significantly improved mechanical properties over conventional alloys, such as high strength-weight ratio, fracture resistance, high-temperature strength and structural stability. Furthermore, HEAs have been proposed to possess significantly enhanced irradiation tolerance. The inherent disorder (or random arrangement of different elements) could mitigate damage by annihilating Frenkel pairs at early stages of cascade events. However, radiation damage studies of HEAs are extremely limited. This proposed work will systematically study the irradiation performance of nanostructured steels and HEAs, assess their potential applications in LWRs and advanced fast reactors as structural materials or fuel cladding, and establish/enhance our fundamental understanding of irradiation effects in these materials. The establishment of irradiation performance of novel advanced materials with appealing properties will impact the life extension of current reactors and the development of advanced reactors. The project will use ion irradiation to mimic neutron irradiation. Note that this project will only include ion irradiation due to the large number of sample sets involved, and detailed post-irradiation examination will be proposed in future proposals. The project will include 6 sets of samples: (1) CG 304 steel; (2) UFG 304 steel; (3) NC 304 steel; (4) UFG FeCrNiCo HEA; (5) UFG FeCrNiCoMn HEA; (6) UFG Fe30Ni30Co30Mn10 HEA. CG steels provide a baseline for comparison to UFG and NC steels. Irradiation behavior of the three HEAs with different compositions will be compared to study the effect of composition on irradiation tolerance. We fully recognize that Co is present in the HEAs to be studied and that Co element is not suitable for nuclear application due to long-term activation issues, however, they are used for this project to demonstrate the concept of enhanced irradiation tolerance of HEAs. All 6 sample sets will be irradiated in the Ion Beam Laboratory at University of Wisconsin - Madison. Two irradiation conditions will be utilized for each sample set: 300 oC, 50 dpa; 500 oC, 50 dpa. Fe +2 ion will be used for the ion irradiation. The expected period of performance of the project is Jan. – Feb. 2017. |
| Award Announced Date | 2016-12-16T07:49:06.247 |
| Awarded Institution | Center for Advanced Energy Studies |
| Facility | Microscopy and Characterization Suite |
| Facility Tech Lead | Kumar Sridharan, Yaqiao Wu |
| Irradiation Facility | None |
| PI | Haiming Wen |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 865 |