About this Abstract |
Meeting |
MS&T23: Materials Science & Technology
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Symposium
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High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond IV
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Presentation Title |
Thermal Properties and Calcium-Magnesium-Aluminosilicate (CMAS) Corrosion Resistance of High Entropy Rare-earth Phosphate (Lu0.2Yb0.2Er0.2Y0.2Gd0.2)PO4: A Novel Environmental Barrier Coating (EBC) Candidate |
Author(s) |
Keith C. Bryce, Yueh-Ting Shih, Liping Huang, Jie Lian |
On-Site Speaker (Planned) |
Keith C. Bryce |
Abstract Scope |
Single-phase (Lu0.2Yb0.2Er0.2Y0.2Gd0.2)PO4 was synthesized, and the thermal properties and CMAS resistance were investigated to explore its potential as an EBC candidate. (Lu0.2Yb0.2Er0.2Y0.2Gd0.2)PO4 displays a lower thermal conductivity (2.86 W m-1 K-1 at 1250 K) than all the single-component xenotime phase rare-earth phosphates. Interaction of (Lu0.2Yb0.2Er0.2Y0.2Gd0.2)PO4 with CMAS at 1300 °C for 45 hours led to the formation of a dense and uniformed 40 µm thick Ca8MgRE(PO4)7 reaction layer, which halted CMAS penetration into the bulk pellet. This reaction layer is thinner than the 46 µm and 51 µm thick reactions layers formed by LuPO4 and YPO4 respectively under the same reaction conditions, indicating improved CMAS corrosion resistance. At 1400 and 1500 °C the (Lu0.2Yb0.2Er0.2Y0.2Gd0.2)PO4-CMAS reaction showed CMAS penetrating beyond the reaction layer into the bulk pellet via the grain boundaries, and SiO2 precipitates remaining at the pellet surface. |