Entropy-stable RE2O3-AO2-B2O5 oxide ceramic and preparation method thereof

Abstract

The invention discloses entropy-stabille RE2O3-AO2-B2O5 oxide ceramic and a preparation method thereof, and the preparation method comprises the following steps: taking raw material rare earth oxides RE2O3, AO2 (A = Ti, Zr, Hf, Sn, Th and Ce) and B2O5 (B = V, Nb, Ta and P), calcining, cooling, carrying out ball milling, drying, sieving to obtain powder, carrying out spark plasma sintering, and finally carrying out heat preservation, annealing and carbon removal to obtain the compact RE2O3-AO2-B2O5 rare earth oxide ceramic which takes RE2A2O7 and RE3BO7 as matrixes and is of a fluorite type or pyrochlore type structure is obtained. The fluorite type or pyrochlore type rare earth oxide ceramic material which is high in lattice defect concentration, low in heat conductivity, high in hardness, excellent in fracture toughness, high in phase purity and high in density is prepared by regulating and controlling the stoichiometric ratio of different metal elements and through the steps of high-temperature, high-pressure and short-time sintering; and the material can be applied to the fields of thermal barrier coatings, environmental barrier coatings, solid oxide fuel cells, nuclear waste storages and the like.

Description

technical field [0001] The invention relates to the technical field of functional ceramic materials, in particular to an entropy-stabilized RE 2 o 3 -AO 2 -B 2 o 5 Oxide ceramics and methods for their preparation. Background technique [0002] High-temperature structural ceramics require materials with high melting point, excellent high-temperature stability, outstanding mechanical properties (high hardness, high Young's modulus and high fracture toughness) and chemical stability. The advantages of low material preparation cost, simple preparation process and wide source of raw materials can further promote the large-scale application of materials. [0003] Rare earth oxide ceramic materials with fluorite-type and pyrochlore-type structures have been applied in many fields, such as high-temperature blade surface protective coatings, rocket engine protective coatings and acid and alkali corrosion protection, solid oxide fuel cells, nuclear waste storage and wear-resista...

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Problems solved by technology

[0004] In view of the above-mentioned shortcoming of prior art, the object of the present invention is to provide a kind of entropy stable RE 2 o 3 -AO 2 -B 2 o 5 Oxide ceramics and their preparation methods, by increasing the concentration of lattice point defects in ceramic materials, high temperature stability, and optimizing other thermal properties, while ensuring excellent mechanical properties (such as high hardness and high fracture toughness, etc.) as the key to structural ceramic materials parameters) to solve the problems of poor high-temperature stability, poor nuclear radiation resistance, high high-temperature thermal conductivity, insufficient thermal expansion coefficient, and insufficient oxygen transport capacity of rare earth oxide ceramic materials with fluorite-type and pyrochlore-type structures in the prior art.

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