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Open Access Research Article Issue
Enhanced thermal conductivity and mechanical properties of 2D Cf/SiC composites modified by in-situ grown carbon nanotubes
Journal of Advanced Ceramics 2024, 13 (1): 19-33
Published: 18 January 2024
Downloads:176

In this work, the effects of carbon nanotubes (CNTs) on the microstructure evolution, thermal conductivity, and mechanical properties of Cf/SiC composites during chemical vapor infiltration (CVI) densification were investigated in detail. Compared with composites without CNTs, the thermal conductivity, flexural strength, flexural modulus, fracture toughness, interfacial shear strength, and proportional limit stress of specimens with CNTs of 4.94 wt% were improved by 117%, 21.8%, 67.4%, 10.3%, 36.4%, and 71.1%, respectively. This improvement was attributed to the role of CNTs in the division of inter-layer pores, which provided abundant vapor growth sites for the ceramic matrix and promoted densification of the whole composite. In addition, the high thermal conductivity network formed by the overlap of CNTs and the rivet strengthening effect of CNTs were beneficial for synergistic improvement of thermal conductivity and mechanical properties of the composites. Therefore, this study has practical significance for the development of thermal protection composite components with enhanced thermal conductivity and mechanical characteristics.

Open Access Review Issue
Long-term ceramic matrix composite for aeroengine
Journal of Advanced Ceramics 2022, 11 (9): 1343-1374
Published: 05 September 2022
Downloads:656

Three strategies were proposed to prolong the service life of continuous fiber-reinforced silicon carbide ceramic matrix composite (CMC-SiC), which served as thermal-structure components of aeroengine at thermo-mechanical-oxygenic coupling environment. As for some thermal-structure components with low working stress, improving the degree of densification was crucial to prolong the service life, and the related process approaches were recited. If the thermal-structure components worked under moderate stress, the matrix cracking stress (σmc) should be improved as far as possible. The fiber preform architecture, interface shear strength, residual thermal stress, and matrix strengthening were associated with σmc in this review. Introducing self-healing components was quite significant with the appearance of matrix microcracks when CMC-SiC worked at more severe environment for hundreds of hours. The damage can be sealed by glass phase originating from the reaction between self-healing components and oxygen. The effective self-healing temperature range of different self-healing components was first summarized and distinguished. The structure, composition, and preparation process of CMC-SiC should be systematically designed and optimized to achieve long duration target.

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