About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Environmental Degradation of Multiple Principal Component Materials
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Presentation Title |
Limitations of Equiatomic Refractory High Entropy Alloys: Role of Reactive Elements in Al-containing HfNbTaTiZr |
Author(s) |
Elaf A. Anber, David Beaudry, Daniel Foley, Lavina Backman, Michael Waters, Jean Phillippe Couzinie, James Rondinelli, Elizabeth Opila, Mitra Taheri |
On-Site Speaker (Planned) |
Elaf A. Anber |
Abstract Scope |
Refractory high entropy alloys (RHEAs) hold the promise of superior mechanical properties at high temperatures but are plagued by a lack of oxidation resistance. Efforts to improve the oxidation resistance of RHEAs by adding classical passivating elements, such as Cr and Al, have been unsuccessful, largely due to the presence of reactive elements(REs) (i.e. Zr and Hf) in high concentration. Here, we studied the role of Al additions as a means of improving protective oxide scale formation in a RHEAs, using analytical microscopy and Thermodynamic calculations. Critically, we reveal evidence that the presence of reactive elements (Zr and Hf) in high concentration could act against the formation of a continuous Al2O3 scale by blocking the outward diffusion of Al cation. Controlling the concentrations and species of REs opens an avenue for designing RHEAs that are more resistant to oxidation in high temperature environments. |
Proceedings Inclusion? |
Planned: |
Keywords |
Environmental Effects, High-Entropy Alloys, Phase Transformations |