NSUF 20-3026: Investigating the Performance of Refractory High Entropy Alloys Under Irradiation and Mechanical Extremes
Investigating the Performance of Refractory High Entropy Alloys Under Irradiation and Mechanical Extremes
Novel materials that can sustain harsh irradiation environments are sought for upcoming nuclear power systems. Next generation fission reactors require materials of exceptional performance in terms of resistance to the microstructural damage and the consequent mechanical properties degradation when exposed to neutron irradiations. High entropy alloys (HEA) were proposed as structural materials with exceptional mechanical properties compared to conventional alloys. However, the performance of different compositions of these alloys under extreme conditions of coupled irradiation extremes have to be evaluated and understood. Due to the complexity of post characterizing nuclear materials exposed to neutron irradiation, and to prevent activating those materials, dual beam of heavy ion irradiation and low energy helium is used to simulate neutron damage.
In-situ irradiation/transmission electron microscopy is proposed to be performed in the in-situ TEM/irradiation (IVEM-Tandem) facility at the Argonne National Laboratory on different refractory high entropy alloys which are considered as candidate cladding materials for LFR and GFR reactors. The irradiations are to be performed on magnetron deposited nanocrystalline high entropy alloys of equal compositions of W, Ta, Cr and V or W, Ta, Cr, and Fe using dual beam of high energy krypton to mimic neutron damage and low energy helium to mimic transmutation products. The effect of grain size and composition in limiting irradiation-induced defect densities will investigated. Mechanical property tests of the irradiated materials will be performed at the Material Science and Technology Division (MST-8) at Los Alamos National Laboratory using nanomechanical testing on ex-situ ion irradiated samples. Micropillar testing and in-situ SEM/Hardness testing will be performed on samples ex situ irradiated at similar conditions to those in situ irradiated via IVEM-Tandem. The thermal stability of these alloys will also be studied in-situ in the TEM using a double tilt heating holder up to 1273 K. The outcome of this work will answer several outstanding fundamental questions on the performance of refractory high entropy alloys to severe irradiation, thermal and mechanical environments and will have a significant impact on the materials and nuclear fission communities working on designing novel irradiation resistant materials. The expected period to run this project is 9 months starting from January 2020.
Additional Info
| Field | Value |
|---|---|
| Abstract | Investigating the Performance of Refractory High Entropy Alloys Under Irradiation and Mechanical Extremes Novel materials that can sustain harsh irradiation environments are sought for upcoming nuclear power systems. Next generation fission reactors require materials of exceptional performance in terms of resistance to the microstructural damage and the consequent mechanical properties degradation when exposed to neutron irradiations. High entropy alloys (HEA) were proposed as structural materials with exceptional mechanical properties compared to conventional alloys. However, the performance of different compositions of these alloys under extreme conditions of coupled irradiation extremes have to be evaluated and understood. Due to the complexity of post characterizing nuclear materials exposed to neutron irradiation, and to prevent activating those materials, dual beam of heavy ion irradiation and low energy helium is used to simulate neutron damage. In-situ irradiation/transmission electron microscopy is proposed to be performed in the in-situ TEM/irradiation (IVEM-Tandem) facility at the Argonne National Laboratory on different refractory high entropy alloys which are considered as candidate cladding materials for LFR and GFR reactors. The irradiations are to be performed on magnetron deposited nanocrystalline high entropy alloys of equal compositions of W, Ta, Cr and V or W, Ta, Cr, and Fe using dual beam of high energy krypton to mimic neutron damage and low energy helium to mimic transmutation products. The effect of grain size and composition in limiting irradiation-induced defect densities will investigated. Mechanical property tests of the irradiated materials will be performed at the Material Science and Technology Division (MST-8) at Los Alamos National Laboratory using nanomechanical testing on ex-situ ion irradiated samples. Micropillar testing and in-situ SEM/Hardness testing will be performed on samples ex situ irradiated at similar conditions to those in situ irradiated via IVEM-Tandem. The thermal stability of these alloys will also be studied in-situ in the TEM using a double tilt heating holder up to 1273 K. The outcome of this work will answer several outstanding fundamental questions on the performance of refractory high entropy alloys to severe irradiation, thermal and mechanical environments and will have a significant impact on the materials and nuclear fission communities working on designing novel irradiation resistant materials. The expected period to run this project is 9 months starting from January 2020. |
| Award Announced Date | 2020-02-05T14:16:00.633 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Wei-Ying Chen |
| Irradiation Facility | Intermediate Voltage Electron Microscopy (IVEM)-Tandem Facility |
| PI | Osman El Atwani |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 3026 |