About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Dilute Alloying and Impurity Effects on Phase Transformations
|
| Presentation Title |
Alumina Formation Criteria for Low-Al Ductile Single-phase Refractory Multiprincipal Element Alloys |
| Author(s) |
David Beaudry, Elaf Anber, Charlie Brandenburg, Sharon Park, Keith Knipling, Kevin Hemker, Elizabeth Opila, Mitra Taheri |
| On-Site Speaker (Planned) |
David Beaudry |
| Abstract Scope |
As the demand increases for materials that can operate in the next generation of extreme environments, refractory multiprincipal element alloys (RMPEAs) have emerged as promising candidates. Improving oxidation resistance typically requires secondary phases rich in protective oxide formers (Al, Cr, Si) which embrittle the alloys. We uncovered the formation of alumina during high-temperature oxidation of a ductile, single-phase Group IV–V RMPEA containing only 3 at.% Al. Advanced characterization revealed the phase evolution and thermodynamics governing alumina formation in the dilute Al limit across a hierarchical sequence, from local chemical ordering to suboxide phase separation and selective oxidation. Alumina formation criteria were defined in terms of metal–oxygen pair interactions within multiple local oxide layers rather than the bulk formation enthalpies of stoichiometric oxides. These mechanistic insights establish a predictive framework for selective oxidation throughout complex oxide layers and provide guidance for oxidation-resistant RMPEAs with preserved ductility via dilute additions. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Temperature Materials, Environmental Effects, Phase Transformations |