Fully dense nanocrystalline (La0.2Nd0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 high-entropy ceramics fabricated under ultra-high pressure

Mengting Lin; Zhangtian Wu; Ji Zou; Weimin Wang; Wei Ji; Zhengyi Fu

Open Ceramics (Mar 2024)

Fully dense nanocrystalline (La0.2Nd0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 high-entropy ceramics fabricated under ultra-high pressure

Mengting Lin,
Zhangtian Wu,
Ji Zou,
Weimin Wang,
Wei Ji,
Zhengyi Fu

Affiliations

Mengting Lin: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China; Hubei Longzhong Laboratory, Wuhan University of Technology Xiangyang Demonstration Zone, Xiangyang, 441000, China
Zhangtian Wu: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China
Ji Zou: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China
Weimin Wang: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China
Wei Ji: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China; Hubei Longzhong Laboratory, Wuhan University of Technology Xiangyang Demonstration Zone, Xiangyang, 441000, China; Corresponding author. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China.
Zhengyi Fu: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China; Hubei Longzhong Laboratory, Wuhan University of Technology Xiangyang Demonstration Zone, Xiangyang, 441000, China; Corresponding author. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China.

Journal volume & issue: Vol. 17
p. 100552

Abstract

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In this work, nanocrystalline high-entropy ceramics (HECs) were prepared by the combination of combustion synthesis and ultra-high pressure sintering. The prepared high-entropy (La0.2Nd0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 ceramic powder had the average grain size of 11 nm and displayed the disordered defective fluorite structure. The HECs sintered under ultra-high pressure showed the defective fluorite structure, whereas the control samples fabricated by pressureless sintering showed the ordered pyrochlore structure. The HECs sintered under pressure of 10 GPa possessed much smaller grain size than that obtained by pressureless sintering. In particular, the grain size of ceramics sintered under 10 GPa at 600 °C was not significantly larger than that of raw powder and its Vickers hardness was 11.9 GPa. Ultra-high pressure sintering could remarkably increase the density of ceramics and restrain the growth of grains. The plastic deformation under ultra-high pressure was believed as the main densification mechanism for the grain refinement and performance improvement.

Published in Open Ceramics

ISSN: 2666-5395 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Chemical technology: Clay industries. Ceramics. Glass
Website: https://www.journals.elsevier.com/open-ceramics

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