About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
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High Temperature Oxidation of Metals and Ceramics
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Presentation Title |
High Temperature Oxidation Behavior of Equimolar NbTiZr |
Author(s) |
Charlie Brandenburg, David Beaudry, Michael Waters, Lauren Walters, Elaf Anber, Jean-Philippe Couzinie, Loic Perriere, Mitra Taheri, James Rondinelli, Elizabeth Opila |
On-Site Speaker (Planned) |
Charlie Brandenburg |
Abstract Scope |
Refractory Multi-Principal Element Alloys (RMPEAs) are of interest for their favorable mechanical properties at high temperatures, however their oxidation mechanisms are not well understood. The oxidation kinetics of equimolar NbTiZr were studied by thermogravimetric analysis in the temperature range of 900-1250°C in 1% oxygen (balance argon). The oxidation kinetics were non-parabolic at all temperatures but slowed with time. A minimum oxidation rate was observed at 1050°C. Microscopy and X-ray diffraction analysis revealed that the outer oxide scale consisted of TiO2, and complex oxides TiNb2O7 and Zr6Nb2O17. Sample cross sections revealed several distinct layers of a multi-phase oxide microstructure. Spinodal decomposition of the alloy into high oxygen content Zr-rich and low oxygen content Nb-rich regions was observed at the oxide-alloy interface which acted as a template for the inner oxide layers. The observed decomposition is consistent with Monte Carlo simulations. |