A scalable method allows for the rapid fabrication of C/SiC composites with excellent mechanical properties and ablation resistance

C/SiC composites have been identified as significant potential thermal protection materials for aerospace. However, the widespread application of most C/SiC composites is generally limited by their poor balance between rapid, efficient fabrication and superior material performance. Here, we propose a scalable combined process that integrates multistep slurry impregnation (MSI) with a polymer infiltration and pyrolysis (PIP). The MSI process developed in this work enabled the consistent infusion and tight packing of a substantial SiC powder content (34 vol%) within the fiber fabric, leading to a green body with a relative density reaching 64.7 vol%. This densely packed structure was subsequently infiltrated and consolidated by a pyrolytic SiC phase through a rapid PIP cycle, resulting in a composite characterized by high bulk density (2.24 g/cm³) and very low open porosity (2.90%). Notably, the pore size of these C/SiC composites is one to two orders of magnitude smaller than that of those fabricated via conventional PIP methods. The resulting composites display excellent mechanical properties, including a flexural strength of 421±31 MPa and a fracture toughness of 16.33±1.70 MPa·m^1/2. Under exposure to an oxyacetylene flame at 1600–2000 °C, they exhibit exceptionally low mass loss and linear ablation rates, attributed to their minimal porosity and the thermal stability of the integrated matrix at high temperatures. This integrated MSI-PIP technique represents a rapid, efficient, and scalable method for producing high-performance C/SiC composites and is well suited for advanced aerospace applications.