热压烧结（Zr_0.2Ti_0.2Ta_0.2Nb_0.2Cr_0.2）B₂高熵陶瓷的制备与性能

Fabrication and properties of (Zr_0.2Ti_0.2Ta_0.2Nb_0.2Cr_0.2)B₂high-entropy ceramic by hot-press sintering

摘要

采用热压烧结工艺，在1800 ℃条件下成功制备五元高熵硼化物陶瓷（Zr_0.2Ti_0.2Ta_0.2Nb_0.2Cr_0.2）B₂，系统研究其物相组成、微观结构、力学性能及高温稳定性。结果表明：该陶瓷主要由单一高熵固溶体相构成，局部存在微量Zr、Ta富集区。维氏硬度和三点弯曲强度分别达到19.03 GPa和279.76 MPa，断口呈现典型脆性穿晶断裂特征。经1500 ℃、50 h热处理后，高熵陶瓷仍保持稳定的物相组成与微观结构，未出现晶粒长大、相分离或新相析出现象，硬度与强度均未发生显著变化，表明该高熵陶瓷内部各组元间形成了稳定的晶体结构，有效抑制了元素扩散与相变过程，具有良好的高温结构稳定性与力学性能保持能力。

Abstract

The five-component high-entropy boride ceramic (Zr_0.2Ti_0.2Ta_0.2Nb_0.2Cr_0.2)B₂ is successfully prepared via hot-press sintering at 1800 ℃. A systematic investigation is conducted on its phase composition，microstructure，mechanical properties and high-temperature stability. The results show that the ceramic primarily consists of a single high-entropy phase，with minor localized enrichments of Zr and Ta. The Vickers hardness and three-point flexural strength reach 19.03 GPa and 279.76 MPa，respectively，with the fracture surface exhibiting typical brittle transgranular fracture characteristics. After heat treatment at 1500 ℃ for 50 h，the microstructure of the high-entropy ceramic remains stable，showing no grain growth or precipitation of new phases. Neither hardness nor strength undergos significant changes，demonstrating excellent high-temperature structural stability and retention of mechanical properties.

关键词

热压烧结 / 硼化物 / 高熵陶瓷 / 微观结构 / 力学性能

Key words

hot-press sintering / boride / high-entropy ceramic / microstructure / mechanical property

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