About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
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Phase Transformations and Microstructural Evolution
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Presentation Title |
C-25: Property and Microstructure of Ni50.3Ti29.7Hf20 High-temperature Shape Memory Alloys with Different Aging Conditions |
Author(s) |
Jiaqi Dong, Alexander Demblon, Tejas Umale, Dexin Zhao, Gianna Valentino, Ibrahim Karaman, Kelvin Xie |
On-Site Speaker (Planned) |
Jiaqi Dong |
Abstract Scope |
NiTiHf is a class of promising high-temperature shape memory alloys that find many aerospace applications. However, the relationship between microstructure and thermomechanical properties of NiTiHf subjected to various aging conditions is unclear. In this work, we used the Ni50.3Ti29.7Hf20 SMA as the model system. Aging at different temperatures induced the growth of precipitates with different sizes. We observed that the presence of precipitates refines the martensite plates, reduces the martensite variant numbers, and changes the orientation relationship between the martensite plates compared with the solution-treated counterpart. Furthermore, the aged samples exhibited higher transformation temperatures, narrower phase transformation temperature windows, improved thermal stability, and retained or even improved transformation strain. The improved thermomechanical properties observed in the aged samples are explained by the submicron and nanometer-scale microstructure resulting from the aging process. The findings of this study offer new information on the processing-property-microstructure relationship in NiTiHf-based SMAs. |
Proceedings Inclusion? |
Planned: |
Keywords |
Characterization, Phase Transformations, High-Temperature Materials |