Lightweight SiBCN-modified CBCF composite enables directional heat management for hypersonic thermal protection

The rapid advancement of next-generation aerospace vehicles, designed for extended flight durations and higher speeds, will result in significant aerodynamic heating and considerable mechanical stress due to vibrations, shocks, and thermal loads. Thermal protection systems (TPS) are crucial for maintaining structural integrity, operational efficiency, and the safety of both the vehicle and the high-precision instruments used in hypersonic flight. Aerospace engineers have long sought materials capable of withstanding the extreme temperatures generated by hypersonic flight. Carbon-bonded carbon fiber (CBCF) composites are ideal for their lightweight and high porosity structure, thermal insulation properties, and exceptional dimensional stability at elevated temperatures. But their restricted in-plane heat dissipation capacity poses a critical challenge for applications under extreme thermal gradients. This shortcoming has necessitated the development of innovative strategies to enhance directional heat-leading capabilities and achieve efficient thermal management.

Recently, a team of material scientists led by Baosheng Xu from Beijing Institute of Technology, China developed SiBCN-modified CBCF composites (CBCF/SiBCN) that integrates high-efficiency in-plane heat conduction pathways with an anisotropic thermal insulation structure, analogous to dredging thermal protection mechanisms that redirect aerodynamic heat flux from high-stress stagnation points to cooler regions. This wok not only introduces a modified thermal conduction design for CBCF materials but also conducts a comprehensive investigation into the mechanical properties, thermal conductivity, and fabrication processes of the CBCF/SiBCN composites. Furthermore, it anticipates their potential in multifunctional thermal protection in aerospace applications.

The team published their work in Journal of Advanced Ceramics on June 11, 2025.

“Through microstructural design of CBCF and modification with SiBCN ceramics, we developed a material that effectively directs heat flow in the plane while obstructing it through the thickness,” explains Baosheng Xu, corresponding author of the study, Associate professor at the Institute of Advanced Structure Technology at Beijing Institute of Technology (China), a senior expert whose research interests focus on the field of lightweight and multifunctional thermal protection material. “This design is analogous to dredging thermal protection, rapidly dissipating heat from high-flux areas to cooler regions.”

The composite demonstrates remarkable performance: in-plane thermal conductivity reaches 60.9–61.5 W/m·K, while through-the-thickness conductivity remains low at 0.08 W/m·K. Compressive strengths are 4.05–4.36 MPa in the in-plane direction and 1.30–1.36 MPa through the thickness, with a density of just 0.48–0.49 g/cm³. Infrared thermal imaging tests revealed that samples with heat-leading layers distributed heat uniformly under unilateral heating, whereas unmodified composites developed hotspots.

“The modified in-plane heat leading structure integrates heat conduction and insulation,” says Xu. “The thermal dredging ability is significantly improved compared with the conventional CBCF composites. This synergy could revolutionize TPS design for hypersonic vehicles.”

However, more in-depth research is still required to explore the application potential of CBCF/SiBCN composites as advanced thermal protection materials. In this context, the research team has proposed key development directions for future work, including enhancing high-temperature oxidation resistance, optimizing microstructural design and improving large-scale preparation processes.

Other contributors include Xinqiao Wang, Wentao Wu, Yan Zhang, Baolu Shi from the Institute of Advanced Structure Technology at Beijing Institute of Technology in Beijing, China; Bin Ma from Beijing Institute of Spacecraft System engineering in Beijing, China; Xiaoguang Luo from China Academy of Aerospace Aerodynamics in Beijing, China; Ning Zhou from the Institute of Advanced Structure Technology at Beijing Institute of Technology in Beijing, China.

This work was supported by the National Natural Science Foundation of China (nos. 52472063 and 12090031). The authors would like to acknowledge the Fundamental Research Funds for the Central Universities for their support.

About Author

Dr. Baosheng Xu is an Associate Professor at Institute of Advanced Structure Technology, Beijing Institute of Technology. His research focuses on new thermal protection materials and structures in high and low temperature environment, including the design, preparation and performance evaluation of new aerogels, special coatings, new non-rigid thermal insulation materials and structures, new low temperature resistant resin and its composite materials. Have published about 100 SCI-expanded journal papers.

Miss Xinqiao Wang is a PhD student of Institute of Advanced Structure Technology, Beijing Institute of Technology. Her research focuses on advanced thermal protection materials for aerospace applications.

About Journal of Advanced Ceramics

Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen. JAC’s 2023 IF is 18.6, ranking in Top 1 (1/31, Q1) among all journals in “Materials Science, Ceramics” category, and its 2024 CiteScore is 25.9 (5/130) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508