About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
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Environmental Degradation of Multiple Principal Component Materials
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Presentation Title |
Evaluation of a Nb-Si-Ti-Al-Hf Alloy as a Bond Coat for Nb-based Alloys |
Author(s) |
Collin S. Holgate, Melina A Endsley, Andrew G Hattoon, Akane Suzuki, Michael Worku, Carlos G Levi, Tresa M Pollock |
On-Site Speaker (Planned) |
Collin S. Holgate |
Abstract Scope |
Refractory alloys offer exciting opportunities to enhance the efficiency of gas turbine engines by replacing current Ni-based superalloys in the hot section. However, existing bond coat alloys have inadequate temperature capability and are thermochemically incompatible with refractory alloys, motivating the development of new protective bond coatings. Selected alloys in the NbSiTiAlHf system, identified by a computational-experimental approach, exhibit exceptional isothermal oxidation behavior by forming a continuous alumina scale up to 1400°C. The present study further characterizes the performance of one such alloy, with the goal of assessing its potential as a bond coat. The oxide scale’s durability is assessed with cyclic oxidation experiments at 800°C, 1200°C, and 1400°C. Modeling stress states in the alloy and alumina scale provided further context, which was enabled by dilatometry measurements of the alloy’s coefficient of thermal expansion. Finally, interdiffusion behavior with a candidate structural alloy, C-103, is discussed. |
Proceedings Inclusion? |
Planned: |