About this Abstract |
Meeting |
MS&T23: Materials Science & Technology
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Symposium
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High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond IV
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Presentation Title |
High-Temperature Oxidation of Refractory High Entropy Alloys: Role of Reactive Elements on Scale formation. |
Author(s) |
Elaf A. Anber, David Beaudry, Sebastian Lech, Nathan Smith, Michael Joseph Waters, Loic Perriere, Jean-Phillippe Couzinie, James Rondinelli, Chris Wolverton, Elizabeth Opila, Mitra L 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 passivation elements, such as Cr and Al, have been unsuccessful, largely due to the inability to form a continuous protective oxide scale, or the formation of deleterious secondary phases. High resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) have been used to investigate the role of REs addition on scale formation. Critically, we reveal evidence that the presence of reactive elements (Zr and Hf) in high concentrations could act against the formation of a continuous Al2O3 scale by blocking the outward diffusion of metal cations. The results may find broader applicability for manipulating the RHEAs design via controlling the concentrations and species of reactive elements. |