Yang Qian, Li Cuiyan, Ouyang Haibo, Gao Ruinan, Shen Tianzhan, Huang Jianfeng
Key Laboratory for Green Manufacturing & Functional Application of Inorganic Materials, School of Materials Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
Materials (Basel). 2023 Mar 21;16(6):2495. doi: 10.3390/ma16062495.
Porous (TaNbTiZrHf)C high-entropy ceramics (HEC) with a dual-porosity structure were fabricated by pressureless sintering using a mixture powder of ceramic precursor and SiO microspheres. The carbothermal reduction in the ceramic precursor led to the formation of pores with sizes of 0.4-3 μm, while the addition of SiO microspheres caused the appearance of pores with sizes of 20-50 μm. The porous HECs exhibit competitive thermal insulation (4.12-1.11 W·m k) and extraordinary compressive strength (133.1-41.9 MPa), which can be tailored by the porosity of the ceramics. The excellent properties are ascribed to the high-entropy effects and dual-porosity structures. The severe lattice distortions in the HECs lead to low intrinsic thermal conductivity and high compressive strength. The dual-porosity structure is efficient at phonon scattering and inhabiting crack propagations, which can further improve the thermal insulation and mechanical properties of the porous HECs.
采用陶瓷前驱体与SiO微球的混合粉末通过无压烧结制备了具有双孔隙结构的多孔(TaNbTiZrHf)C高熵陶瓷(HEC)。陶瓷前驱体中的碳热还原导致形成尺寸为0.4 - 3μm的孔隙，而SiO微球的加入则导致出现尺寸为20 - 50μm的孔隙。多孔HEC表现出具有竞争力的隔热性能(4.12 - 1.11W·m⁻¹·K⁻¹)和出色的抗压强度(133.1 - 41.9MPa)，这可以通过陶瓷的孔隙率进行调整。这些优异性能归因于高熵效应和双孔隙结构。HEC中严重的晶格畸变导致低本征热导率和高抗压强度。双孔隙结构在声子散射和抑制裂纹扩展方面效率很高，这可以进一步提高多孔HEC的隔热和力学性能。
