About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Environmental Degradation of Multiple Principal Component Materials
|
Presentation Title |
Effect of the Chemical Composition on the Formation of Compact (Cr,Ta,Ti)O2 Scales on Refractory High-entropy Alloys (RHEAs) within the Ta-Mo-Cr-Ti-Al System |
Author(s) |
Steven Schellert, Hans-Jürgen Christ, Stephan Laube, Alexander Kauffmann, Martin Heilmaier, Bronislava Gorr |
On-Site Speaker (Planned) |
Steven Schellert |
Abstract Scope |
RHEAs are potential candidates for high temperature applications. The superior oxidation resistance of the equiatomic TaMoCrTiAl relies on the formation of a (Cr,Ta,Ti)O2 scale. In this contribution, various alloys within the Ta-Mo-Cr-Ti-Al system with different Ta, Cr, Al and Ti contents as well as a Mo-free alloy are investigated to understand the influence of the chemical composition on the formation of Cr,Ta,Ti)O2. It was found that the elements Cr and Ta are indispensable to form a compact (Cr,Ta,Ti)O2 layer. At least 15 at.% Cr and Ta are required to guarantee the (Cr,Ta,Ti)O2 formation, at lower concentrations mixed oxides are formed. It is assumed that Al concentrations higher 15 at.% support the (Cr,Ta,Ti)O2 formation owing to getter and nucleation effects. The removal of Mo causes enhanced internal oxidation due to the unfavorable changes in the microstructure. Ti exhibits a positive effect by reducing the concentration of oxygen vacancies in the oxide. |
Proceedings Inclusion? |
Planned: |
Keywords |
High-Entropy Alloys, High-Temperature Materials, Characterization |