NSUF 24-5113: Investigating ion irradiation at high temperatures on high entropy carbide ceramics using correlative positron annihilation spectroscopy and transmission electron microscopy
High entropy carbides (HECs) are an emerging class of ultra-high temperature ceramics with high hardness, increased oxidation resistance, complex thermal behavior, and robust irradiation tolerance. This project seeks to reveal the high dose and high temperature ion irradiation behavior of HECs concerning phase stability, vacancy formation/clustering, and void swelling using 5 MeV Zr ions. This will be investigated using correlative positron annihilation lifetime spectroscopy (PALS) and transmission electron microscopy (TEM). It is hypothesized that the chemically complex energy landscape of the HEC lattice impacts the formation and migration of vacancies and interstitials in the material. Previous irradiation studies of HECs primarily observed lattice expansion and dislocation loop formation. By irradiating the material to higher damage levels (100 dpa) and at higher temperatures (500-1,000 °C) than previously reported, the resistance to void swelling and irradiation-induced vacancy formation can be studied under advanced reactor-relevant conditions (GFR, VHTR). These conditions have yet to be reported and have the potential to significantly further the understanding of these materials. PALS is a powerful technique that is unique in its ability to measure defects from single vacancies to nanovoids that has yet to be used on HECs. PALS combined with TEM can be used to reveal fundamental details about the development of ion irradiation induced defects in HECs as a function of temperature. The outcome of this project is a significant increase in the knowledge of ion irradiation induced voids, along with the first reported irradiation experiments done above ~20 dpa and 800 °C in HECs.
추가 정보
| 필드 | 값 |
|---|---|
| Award Announced Date | 2024-09-23T12:11:35.47 |
| Awarded Institution | North Carolina State University |
| Facility Tech Lead | Ayman Hawari , Lin Shao |
| Irradiation Facility | Accelerator Laboratory |
| PI | Caleb Schenck |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | None |