Study on the ablation performance of SiC-coated high thermal conductivity three-dimensional C/C composites

Carbon/carbon composites were prepared by densifying a three-dimensional preform made of mesophase pitch-based carbon fiber woven fabric lamination and PAN-based carbon fiber z-pin. Afterwards, SiC coating was prepared on them by pack cementation, and their ablation performances were investigated. Results show that the stacked of pitch-based carbon fiber woven fabrics in Z direction induces a high thermal conductivity of composites in in-plane direction and a sawtooth-structured surface of SiC coating, which helps to decrease the surface temperature (from 1778 to 1614 ℃) and the thermal stress of coating during ablation. Thus, a greatly improved ablation resistance is obtained for the coating in the X-Z plane, showing a mass ablation rate of − 0.01 mg/s and a linear ablation rate of − 0.12 µm/s, respectively, 90.9% and 105.2% lower than that of the X-Y plane. Our findings can provide a meaningful way for the development of high-performance ablation-resistant C/C composites.