首页|ZrC-SiC closed-cell ceramics with low thermal conductivity:Exploiting unique spherical closed-cell structure through tape casting and CVI techniques

ZrC-SiC closed-cell ceramics with low thermal conductivity:Exploiting unique spherical closed-cell structure through tape casting and CVI techniques

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Porous ultra-high temperature ceramics(UHTCs)are recognized as novel candidates for fulfilling the requirements of thermal protection systems of hypersonic aircrafts,as they possess excellent high-temperature resistance and low thermal conductivity.Currently,the reported porous UHTCs predomi-nantly exhibit an open pore structure.By contrast,closed-cell UHTCs,formed by employing ceramic hol-low microspheres(HMs)as pore-forming agents,hold great potential for achieving superior thermal insu-lation performance.Unfortunately,the implementation of this strategy has been hindered by the scarcity of raw materials and preparation techniques.In this paper,ZrC-SiC closed-cell ceramics were first successfully prepared through a combination of tape casting and chemical vapor infiltration(CVI)techniques,utilizing the self-developed ZrC HMs as the primary raw material.The morphology,microstructure,and thermal insulation properties of the obtained ZrC-SiC closed-cell ceramics were investigated.The results indicate that when the content of ZrC HMs is 30 vol.％,the density of the prepared porous ceramics is 2.09 g cm-3,with a closed porosity of 14.05％and a thermal conductivity of 1.69 W(m K)-1.The results clearly prove that the CVI process can success-fully convert ZrC HMs into closed pore structures within porous ceramics.The introduction of ZrC HMs suppresses the contribution of free electrons to thermal conductivity and brings about a large number of solid-gas interfaces,which increases the interfacial thermal resistance and significantly reduces the phonon thermal conductivity.Consequently,the as-prepared ZrC-SiC closed-cell ceramics show excellent thermal insulation properties.This study provides a new idea and method for the development of porous UHTCs and offers a more reliable material choice for thermal protection systems.

Closed-cell ceramicsUHTCsThermal insulationZrC hollow microspheresCVIInterfacial thermal resistance

Kai Zhao、Fang Ye、Laifei Cheng、Jinsong Yang

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Science and Technology on Thermostructural Composite Materials Laboratory,Northwestern Polytechnical University,Xi'an 710072,China

National Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of China111 Project of ChinaScience Center for Gas Turbine Project

520723045187222952172100B08040P2022-B-Ⅳ-002-001

2024

10.1016/j.jmst.2023.09.042

材料科学技术(英文版)
中国金属学会 中国材料研究学会 中国科学院金属研究所

材料科学技术(英文版)

CSTPCD
影响因子：0.657
ISSN：1005-0302
年,卷(期)：2024.184(17)
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