Effects of In Situ Grown SiC on the Microstructure and Anti‐Ablation Performance of C/C–SiC Composites Fabricated by Sol–Gel and Precursor Impregnation and Pyrolysis

Abstract

With the use of a novel precursor, SiC granules together with nanofibers were grown in situ in C/C felt utilizing sol–gel and precursor impregnation and pyrolysis methods. The results showed that the precursor possessed low residual carbon after the carbothermal reduction reaction. Moreover, owing to the gas–gas reaction between SiO and CO, the generated SiC largely filled the microvoids in the regions of the non‐woven layer. Furthermore, the in situ grown SiC of the composites was more continuous than the nubby SiC of polycarbosilane because of the uniform filling of SiC particles and nanofibers. All these factors are conducive to the formation of a compact layer of SiO2 during ablation by increasing the molten glass and impeding the infiltration of O2. As a result, the fabricated C/C–SiC composites exhibited better ablation resistance, and the linear and mass ablation rates were 7.284 ± 0.307 μm s−1 and 0.218 ± 0.023 mg s−1, respectively, after ablation for 120 s.