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Research Article | Open Access

High entropy defective fluorite structured rare-earth niobates and tantalates for thermal barrier applications

Zifan ZHAOa,bHeng CHENaHuimin XIANGaFu-Zhi DAIaXiaohui WANGcWei XUdKuang SUNdZhijian PENGb( )Yanchun ZHOUa( )
Science and Technology on Advanced Functional Composite Laboratory, Aerospace Research Institute of Materials & Processing Technology, Beijing 100076, China
School of Engineering and Technology, China University of Geosciences, Beijing 100083, China
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
Shanghai Chenhua Science and Technology Corporation Ltd., Shanghai 201804, China
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Rare-earth tantalates and niobates (RE3TaO7 and RE3NbO7) have been considered as promising candidate thermal barrier coating (TBC) materials in next generation gas-turbine engines due to their ultra-low thermal conductivity and better thermal stability than yttria-stabilized zirconia (YSZ). However, the low Vickers hardness and toughness are the main shortcomings of RE3TaO7 and RE3NbO7 that limit their applications as TBC materials. To increase the hardness, high entropy (Y1/3Yb1/3Er1/3)3TaO7, (Y1/3Yb1/3Er1/3)3NbO7, and (Sm1/6Eu1/6Y1/6Yb1/6Lu1/6Er1/6)3(Nb1/2Ta1/2)O7 are designed and synthesized in this study. These high entropy ceramics exhibit high Vickers hardness (10.9-12.0 GPa), close thermal expansion coefficients to that of single-principal-component RE3TaO7 and RE3NbO7 (7.9×10-6-10.8×10-6-1 at room temperature), good phase stability, and good chemical compatibility with thermally grown Al2O3, which make them promising for applications as candidate TBC materials.


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Journal of Advanced Ceramics
Pages 303-311
Cite this article:
ZHAO Z, CHEN H, XIANG H, et al. High entropy defective fluorite structured rare-earth niobates and tantalates for thermal barrier applications. Journal of Advanced Ceramics, 2020, 9(3): 303-311.








Web of Science






Received: 22 January 2020
Revised: 14 February 2020
Accepted: 15 February 2020
Published: 05 June 2020
© The Author(s) 2020

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