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High-entropy pyrochlore-type structures based on rare-earth zirconates are successfully produced by conventional solid-state reaction method. Six rare-earth oxides (La2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, and Y2O3) and ZrO2 are used as the raw powders. Five out of the six rare-earth oxides with equimolar ratio and ZrO2 are mixed and sintered at different temperatures for investigating the reaction process. The results demonstrate that the high-entropy pyrochlores (5RE1/5)2Zr2O7 have been formed after heated at 1000 ℃. The (5RE1/5)2Zr2O7 are highly sintering resistant and possess excellent thermal stability. The thermal conductivities of the (5RE1/5)2Zr2O7 high-entropy ceramics are below 1 W·m-1·K-1 in the temperature range of 300-1200 ℃. The (5RE1/5)2Zr2O7 can be potential thermal barrier coating materials.


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High-entropy pyrochlores with low thermal conductivity for thermal barrier coating materials

Show Author's information Fei LILin ZHOUJi-Xuan LIUYongcheng LIANGGuo-Jun ZHANG( )
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Institute of Functional Materials, College of Science, Donghua University, Shanghai 201620, China

† These authors contributed equally to this work.

Abstract

High-entropy pyrochlore-type structures based on rare-earth zirconates are successfully produced by conventional solid-state reaction method. Six rare-earth oxides (La2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, and Y2O3) and ZrO2 are used as the raw powders. Five out of the six rare-earth oxides with equimolar ratio and ZrO2 are mixed and sintered at different temperatures for investigating the reaction process. The results demonstrate that the high-entropy pyrochlores (5RE1/5)2Zr2O7 have been formed after heated at 1000 ℃. The (5RE1/5)2Zr2O7 are highly sintering resistant and possess excellent thermal stability. The thermal conductivities of the (5RE1/5)2Zr2O7 high-entropy ceramics are below 1 W·m-1·K-1 in the temperature range of 300-1200 ℃. The (5RE1/5)2Zr2O7 can be potential thermal barrier coating materials.

Keywords:

thermal barrier coating (TBC), pyrochlore, high-entropy ceramics, thermal conductivity
Received: 05 June 2019 Accepted: 18 June 2019 Published: 25 July 2019 Issue date: December 2019
References(28)
[1]
W Pan, SR Phillpot, CL Wan, et al. Low thermal conductivity oxides. MRS Bull 2012, 37: 917-922.
[2]
NP Padture, M Gell, EH Jordan. Thermal barrier coatings for gas-turbine engine applications. Science 2002, 296: 280-284.
[3]
R Vaßen, MO Jarligo, T Steinke, et al. Overview on advanced thermal barrier coatings. Surf Coat Technol 2010, 205: 938-942.
[4]
DR Clarke, SR Phillpot. Thermal barrier coating materials. Mater Today 2005, 8: 22-29.
[5]
R Vassen, XQ Cao, F Tietz, et al. Zirconates as new materials for thermal barrier coatings. J Am Ceram Soc 2004, 83: 2023-2028.
[6]
W Guo, S Ma, L Liu, et al. CMAS corrosion and protection of thermal barrier coatings for aeroengine. Adv Ceram 2017, 38: 159-175. (in Chinese)
[7]
B Liu, YC Liu, CH Zhu, et al. Advances on strategies for searching for next generation thermal barrier coating materials. J Mater Sci Technol 2019, 35: 833-851.
[8]
L Chen, G-J Yang. Epitaxial growth and cracking of highly tough 7YSZ splats by thermal spray technology. J Adv Ceram 2018, 7: 17-29.
[9]
M Zhao, W Pan, CL Wan, et al. Defect engineering in development of low thermal conductivity materials: A review. J Eur Ceram Soc 2017, 37: 1-13.
[10]
L Yang, CH Zhu, Y Sheng, et al. Investigation of mechanical and thermal properties of rare earth pyrochlore oxides by first-principles calculations. J Am Ceram Soc 2019, 102: 2830-2840.
[11]
R Witte, A Sarkar, R Kruk, et al. High-entropy oxides: An emerging prospect for magnetic rare-earth transition metal perovskites. Phys Rev Mater 2019, 3: 034406.
[12]
CM Rost, E Sachet, T Borman, et al. Entropy-stabilized oxides. Nat Commun 2015, 6: 8485.
[13]
M-H Tsai, J-W Yeh. High-entropy alloys: A critical review. Mater Res Lett 2014, 2: 107-123.
[14]
X-F Wei, J-X Liu, F Li, et al. High entropy carbide ceramics from different starting materials. J Eur Ceram Soc 2019, 39: 2989-2994.
[15]
BL Ye, TQ Wen, MC Nguyen, et al. First-principles study, fabrication and characterization of (Zr0.25Nb0.25Ti0.25V0.25)C high-entropy ceramics. Acta Mater 2019, 170: 15-23.
[16]
J Gild, YY Zhang, T Harrington, et al. High-entropy metal diborides: A new class of high-entropy materials and a new type of ultrahigh temperature ceramics. Sci Rep 2016, 6: 37946.
[17]
Y Qin, J-X Liu, F Li, et al. A high entropy silicide by reactive spark plasma sintering. J Adv Ceram 2019, 8: 148-152.
[18]
J Gild, J Braun, K Kaufmann, et al. A high-entropy silicide: (Mo0.2Nb0.2Ta0.2Ti0.2W0.2)Si2. J Materiomics 2019, .
[19]
J Gild, M Samiee, JL Braun, et al. High-entropy fluorite oxides. J Eur Ceram Soc 2018, 38: 3578-3584.
[20]
SC Jiang, T Hu, J Gild, et al. A new class of high-entropy perovskite oxides. Scripta Mater 2018, 142: 116-120.
[21]
J Dąbrowa, M Stygar, A Mikuła, et al. Synthesis and microstructure of the (Co,Cr,Fe,Mn,Ni)3O4 high entropy oxide characterized by spinel structure. Mater Lett 2018, 216: 32-36.
[22]
GJ Zhang, L Zhou, F Li, et al. Synthesis of high entropy ceramic powders for thermal barrier coating. Chinese Patent, Application Number 201910410275.5, May 17 2019.
[23]
MA Subramanian, G Aravamudan, GV Subba Rao. Oxide pyrochlores—A review. Prog Solid State Chem 1983, 15: 55-143.
[24]
ZJ Wang, GH Zhou, DY Jiang, et al. Recent development of A2B2O7 system transparent ceramics. J Adv Ceram 2018, 7: 289-306.
[25]
H Lehmann, D Pitzer, G Pracht, et al. Thermal conductivity and thermal expansion coefficients of the lanthanum rare-earth-element zirconate system. J Am Ceram Soc 2003, 86: 1338-1344.
[26]
BS Murty, JW Yeh, S Ranganathan, et al. High-entropy alloys: Basic concepts. In: High-Entropy Alloys, 2nd edn. BS Murty, JW Yeh, S Ranganathan, et al. Eds. Elsevier, 2019: 13-30.
[27]
M Zhao, XR Ren, J Yang, et al. Low thermal conductivity of rare-earth zirconate-stannate solid solutions (Yb2Zr2O7)1−x(Ln2Sn2O7)x (Ln = Nd, Sm). J Am Ceram Soc 2016, 99: 293-299.
[28]
XQ Cao, R Vassen, F Tietz, et al. New double-ceramic-layer thermal barrier coatings based on zirconia-rare earth composite oxides. J Eur Ceram Soc 2006, 26: 247-251.
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Publication history

Received: 05 June 2019
Accepted: 18 June 2019
Published: 25 July 2019
Issue date: December 2019

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© The author(s) 2019

Acknowledgements

Financial support from the National Natural Science Foundation of China (Nos. 51532009, 51602324, and 51872405) are gratefully acknowledged.

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