About this Abstract |
Meeting |
MS&T24: Materials Science & Technology
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Symposium
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Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials
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Presentation Title |
Persistent Free Carbon in Entropy Stabilized Ceramics |
Author(s) |
James A. Wollmershauser, Heonjune Ryou, Kevin Anderson, Eric Patterson, Sara Mills, Homa Keshmiri, Lavina Backman, Boris Feigelson, Edward Gorzkowski |
On-Site Speaker (Planned) |
James A. Wollmershauser |
Abstract Scope |
Entropy stabilized ceramics are a recently developed class of ceramics that have garnered interest due to observations of improved properties over their simple ceramic constituents, i.e. compounds with one metal element. Also called compositionally complex ceramics, these materials are hypothesized to get their exceptional properties from their composition complexity and structure, consisting of four or more metal elements in a single phase ceramic solid solution at or near equimolar concentration. A common route to synthesize these materials is to mix simple ceramic precursors in the desired molar amounts, then heat treating to form a solid solution. However, the assumption that the most stable phase is a near-equimolar composition should be carefully examined, especially considering the anionic element. Using standard processing approaches, (Hf0.2Zr0.2Ta0.2Ti0.2Nb0.2)C is used as a case-study to demonstrate that free carbon already present in constituent carbides persists throughout processing even though the overall composition can be carbon deficient. |