Ablative Properties of SiC_p Doped C_f/Li₂O-Al₂O₃-SiO₂ Composites

In a high heat flux ablative environment, the surface temperature of aircraft rises rapidly, leading to traditional high thermal conductivity materials being ineffective at protecting internal metal components.In this study, continuous carbon fiber reinforced Li 2 O-Al 2 O 3 -SiO 2 (C f /LAS) glass ceramic composites doped with SiC particles (SiC p ) were prepared by slurry immersion winding and hot pressing sintering.Effect of matrix crystallinity on ablative properties of the composites under ultra-high heat flux was investigated.By utilizing heat absorption and low thermal conductivity characteristics associated with SiO 2 gasification within composite materials, both surface and internal temperatures of these materials are effectively reduced, thereby ensuring the safe operation of aircraft and electronic devices.Results indicate that the average linear ablation rate of composites doped with 10% (in mass) of SiC p significantly decreases at a heat flux of 20 MW/m.Transmission electron microscope observation reveals that the doped glass matrix exhibits increased crystallinity, reduced internal stress, and minimized lattice distortion, thereby enhancing the composites' high-temperature performance.However, excessive SiC p doping leads to reduced crystallinity and deteriorated ablation performance.Ultimately, the average linear ablation rate of C f /LAS composites with 10% (in mass) SiC p at 20 MW/m 2 heat flux is comparable to that of commercial carbon/carbon composites, accompanied by providing lower thermal conductivity and higher bending strength.This novel high-performance C f /LAS composite is cost-effective, short-cycled, and suitable for mass production, offering promising potential for widespread application in ablation-resistant components of hypersonic vehicles.