About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Defect Evolution and Phase Stability of Inconel 718 Under Extreme Irradiation and Temperature: A Correlative Positron Annihilation and Transmission Electron Microscopy Study |
| Author(s) |
Fu-Yun Tsai, Caleb Schenck, Ming Liu, Emmanuel Omosegunfunmi Aikulola, Michael Lastovich, Charles Perkins, Zhihan Hu, Benjamin Ernesto Mejia Diaz, Elizabeth J. Kautz, Lin Shao, Bharat Gwalani |
| On-Site Speaker (Planned) |
Fu-Yun Tsai |
| Abstract Scope |
Inconel 718 (IN718) is a candidate structural material for advanced nuclear reactors operating under extreme irradiation and high-temperature conditions. This study examines the microstructural and mechanical evolution of IN718 subjected to 5 MeV C²⁺ ion irradiation at 30, 500, and 850 °C to damage levels up to 100 dpa. Positron annihilation lifetime spectroscopy (PALS) and X-ray diffraction (XRD) show that irradiation at lower temperatures leads to defect saturation and lattice expansion, while irradiation at 850 °C promotes thermal recovery and solute redistribution, resulting in lattice contraction. Transmission electron microscopy (TEM) reveals accelerated phase transformations at high temperature, including the dissolution of ã′ and ã″ precipitates and the formation of stable needle-like ç phase and complex carbides. Microhardness measurements indicate significant irradiation-induced hardening under all conditions, with a maximum hardness of 271.41 ± 25.90 HV at 850 °C and 100 dpa. These findings demonstrate that high-temperature irradiation fundamentally alters precipitation stability in IN718 through defect-mediated phase evolution. |
| Proceedings Inclusion? |
Planned: |