About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
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Environmental Degradation of Multiple Principal Component Materials
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Presentation Title |
High Temperature Oxidation of NbTiZr and HfNbTaTiZr RMPEAs |
Author(s) |
Charlie Brandenburg, David Beaudry, Elaf Anber, Jean-Philippe Couzinie, Loic Perriere, Mitra Taheri, Elizabeth J Opila |
On-Site Speaker (Planned) |
Charlie Brandenburg |
Abstract Scope |
Oxidation mechanisms of refractory multiple principal element alloys (RMPEAs) and methods for mitigating rapid oxidation rates remains a challenge. The oxidation kinetics of equimolar NbTiZr and HfNbTaTiZr were studied by thermogravimetric analysis at 1050°C in 1% oxygen (balance argon). The oxidation kinetics of NbTiZr were non-parabolic but slowed with time, and the sample fully oxidized within the 20-hour TGA experiment. The oxidation kinetics of HfNbTaTiZr were approximately parabolic, and the specific weight gain was significantly less than that of NbTiZr. XRD analysis of the oxide scales revealed TiO2, TiNb2O7, and Zr6Nb2O17 structures in all samples. SEM-EDS of sample cross sections showed initial phase separation of NbTiZr into Nb- and Zr-rich regions, and HfNbTaTiZr into (Nb, Ta) and (Hf, Zr)-rich regions. As oxidation progressed, Ti also precipitated out of solution. Possible explanations for reduced oxidation rates in the HfNbTaTiZr system are explored. |
Proceedings Inclusion? |
Planned: |
Keywords |
High-Temperature Materials, High-Entropy Alloys, Other |