image: The meltable organic precursor coats the surface of Si-Zr particles, pyrolyzes into nanoparticles adsorbed on the surface, and infiltrates into the porous C/C preform along with the molten Si-Zr. Subsequent carbothermal reduction reaction yields nano-dispersion-strengthened C/C-ZrC-SiC composites. During loading, ZrC nanoparticles induce dislocation nucleation and stress-driven 3C→6H-SiC phase transformation, achieving effective matrix strengthening and toughening. Meanwhile, during ablation, these nanoparticles are oxidized to form nano ZrO2, which acts as pinning phases in the amorphous SiO2 scale and triggers martensitic transformation, significantly enhancing resistance to plasma flame erosion.
Credit: Journal of Advanced Ceramics, Tsinghua University Press
Advanced thermal protection systems (TPS) are facing unprecedented performance demands driven by the rapid advancement of aerospace and hypersonic vehicle technologies. TPS materials must withstand mechanical denudation, ultrahigh-temperature ablation and intense airflow scouring. CMCs exhibit remarkable advantages as promising TPS candidates, owing to their high melting points, low thermal expansion and excellent thermal shock resistance. Nevertheless, intrinsic brittleness of ceramic matrix limits atom motion, restricting their mechanical stability and ablation resistance.
To break through the performance bottleneck caused by matrix brittleness and further balance mechanical properties and high-temperature ablation resistance, it is urgent to develop reliable modification methods. Among various reinforcement routes, phase transformation toughening stands out as a promising and feasible strategy. It can consume fracture energy, relieve local stress concentration and inhibit crack propagation through stress-induced structural evolution, which provides an effective solution to improve the comprehensive performance of brittle ceramic materials.
Recently, Prof. Jia Sun's team from Northwestern Polytechnical University, China, reported the fabrication, mechanical and ablation performance of the ZrC nanoparticle reinforced C/C-ZrC-SiC composites, to trigger 3C→6H-SiC polytypic transformation and ZrO2 martensitic transformation, which improves the plasticity of both matrix and the oxide layer.
This work not only explains the formation mechanism of the ZrC nanoparticle reinforced C/C-ZrC-SiC composites and superior mechanical and ablation resistance in extreme thermal environments, but also provides an effective way to enhance plasticity in ceramics and develop advanced nano-dispersion-strengthened CMCs.
The team published their work in Journal of Advanced Ceramics on April 27, 2026.
“In this report, we fabricated the ZrC nanoparticle reinforced C/C-ZrC-SiC composites by a meltable organic-inorganic hybrid infiltration strategy. During melting, organic zirconium acetylacetonate converts to ZrC nanoparticles and uniformly disperses into the matrix driven by the Si-Zr melt.” said Jia Sun, professor at School of Materials Science and Engineering at Northwestern Polytechnical University (China), an expert whose research interests focus on the field of ultra-high temperature ceramics modified C/C composites.
“These ZrC nanoparticles induce abundant dislocation tangles, cross-slip and cutting in the SiC matrix via pinning effects, trigger the formation of deformation twins and gradual 3C→6H SiC phase transformation in the ceramic matrix, which realizes matrix strengthening and toughening. Meanwhile, during ablation, the ZrC nanoparticles are oxidized in situ to form nano ZrO2, which pinning in amorphous SiO2 based oxide scale and occurring martensitic transformation, further enhancing the plastic deformation capacity of the oxide layer to resist plasma flame erosion. The nano-dispersion-strengthened strategy effectively enhances plasticity, mechanical strength, and ablation resistance for C/C-ZrC-SiC composites.” said Prof. Jia Sun.
“The optimized composite exhibits a flexural strength of 207.5 MPa, a fracture toughness of 7.12 MPa·m1/2 and a linear ablation rate of only 0.15 μm·s-1 under plasma ablation. This nanoparticle-induced phase transformation strategy provides a new route for designing tough, anti-ablation CMCs used in extreme thermal environments.” said Prof. Jia Sun.
However, more delicate research works are still needed to explore the interfacial interaction between different nanoparticles and the ceramic matrix in nanoparticle-reinforced composites for TPS applications. In this regard, Prof. Jia Sun also put forward two major works including the ablation resistance in ultrahigh-temperature and high temperature mechanical properties of the composites.
Other contributors include Yuyu Zhang, Dingcong Cui, Xuemeng Zhang, Hongkang Ou, Qiangang Fu from the School of Materials Science and Engineering at Northwestern Polytechnical University, China, and Xin Yang, Qizhong Huang from Central South University, China.
About Author
Jia Sun, Professor, doctoral supervisor of Northwestern Polytechnical University, director of the Office of Shaanxi Key Laboratory of Fiber Reinforced Lightweight Composites. He engages in the research of high-temperature oxidation resistance/environmental barrier coatings on C/C composite, and polymer-derived ceramic-based composites. He has published over 100 SCI papers and authorized 20 national invention patents. He serves as the principal investigator of the National Natural Science Foundation of China, the sub-topic of the Key R&D Plan of the Ministry of Science and Technology, the Pre-research project of the State Administration of Science and Industry for National Defense, the Natural Science Foundation of Shaanxi Province, and the Sino-German Postdoctoral Program. He is also the Editorial Board member of the Journal of Advanced Ceramics, Advanced Powder Materials, Journal of Inorganic Materials, and Advanced Powder Materials (Youth).
Funding
This work was supported by National Defense Basic Scientific Research Program of China (JCKY2022607C007), National Natural Science Foundation of China (52472107, 52432003), National Key R&D Program of Shaanxi Province (2021YFA0715802), and Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University (CX2024006).
DOI LINK：https://doi.org/10.26599/JAC.2026.9221308
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 2024 IF is 16.6, ranking in Top 1 (1/34, 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
Journal
Journal of Advanced Ceramics
Article Title
Nanoparticle-induced phase transformation boosts mechanical and ablation performance for C/C–ZrC–SiC composites
Article Publication Date
27-Apr-2026