About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
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Symposium
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High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond III
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Presentation Title |
Mechanical and Oxidation Behavior of Hf-25Ta-5X Refractory Complex Concentrated Alloys |
Author(s) |
Eric J. Payton, Tinuade Daboiku, Satish Rao, Oleg Senkov |
On-Site Speaker (Planned) |
Eric J. Payton |
Abstract Scope |
Recent work by Perepezko and Yang has indicated that Hf-27Ta forms an adherent and thermal-shock resistant oxide (Hf6Ta2O17) during high temperature oxidation, and Senkov et al have shown that additions of Mo and W while holding this Hf:Ta ratio can increase the high temperature strength in this alloy system. The protective oxide is predicted using ab-initio calculations to also be formed preferentially at lower temperatures, <1500 degrees C. In the present work, we investigate the mechanical properties and oxidation behavior of arc-melted and hot isostatically pressed Hf-25Ta-5X alloys where X=Nb, Zr, Cr, W, Mo, or Mo+W at temperatures lower than 1500 degrees C. The observations are compared against other refractory complex concentrated alloys. It is observed that oxidation behavior of all Hf-25Ta-5X alloys investigated are inferior to Nb-18Ti-10W, and formation of a protective layer of Hf6Ta2O17 is not observed. The underlying reasons for this observation are explored and discussed. |