High-entropy rare-earth niobate ceramics with glassy phase and low thermal conductivity and their preparation method

Abstract

This invention relates to the field of high-entropy ceramic materials technology, specifically to high-entropy rare-earth niobate ceramics with low thermal conductivity in a glassy phase and their preparation method. The invention first uses five oxide powders (Gd₂O₃, Er₂O₃, Ho₂O₃, Yb₂O₃, and Nb₂O₅) as raw materials, or four oxide powders (Er₂O₃, Ho₂O₃, Yb₂O₃, and Nb₂O₅) as raw materials, which are ball-milled and mixed according to a specified ratio. Then, high-entropy niobate powder is synthesized via a high-temperature solid-state reaction method. Finally, dense niobate ceramic materials are obtained through dry pressing and high-temperature sintering. The niobate ceramic material provided by this invention has a defective fluorite phase, extremely low thermal conductivity, a glassy phase thermal conductivity mode, and high hardness and fracture toughness. It can be used as a thermal barrier coating material for the surface of hot-end components in aero-engines.

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