About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
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Symposium
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Advances in Multi-Principal Element Alloys III: Mechanical Behavior
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Presentation Title |
High-temperature Service Performance and Microstructure Evolution of a Nb45Ta25Ti15Hf15 Refractory High-entropy Alloy |
Author(s) |
Gianmarco Sahragard-Monfared, Calvin Belcher, Mingwei Zhang, Cheng Zhang, Andrew Minor, Diran Apelian, Enrique Lavernia, Jeffery Gibeling |
On-Site Speaker (Planned) |
Mingwei Zhang |
Abstract Scope |
The high-temperature service performance of a Nb45Ta25Ti15Hf15 refractory high-entropy alloy (RHEA) was examined within a temperature range of 1123-1223 K under constant true stress creep at 50-300 MPa in a protective argon atmosphere or high vacuum. The RHEA demonstrated significantly improved resistance to creep and exhibited superior creep ductility compared to TiNbHfZrTa (Senkov alloy) and FCC HEAs. Steady-state deformation was identified in all samples and was shown through TEM characterization to be controlled by the motion of long straight screw dislocations. However, the lifespan of tertiary creep depends heavily on the environmental effect: samples subjected to low applied stresses and long duration (specifically in argon atmosphere) experienced phase decomposition and the formation of Hf-oxide at grain boundaries, leading to diminished creep ductility and reduced rupture life compared to those tested under high vacuum. |
Proceedings Inclusion? |
Planned: |
Keywords |
High-Entropy Alloys, High-Temperature Materials, Characterization |