Low-temperature reactive sintering of 3D Cf/in situ ZrC-SiC composites: ablation performance and mechanism in extreme environments

UHTCs are expected to be widely used in the aerospace industry due to their excellent ablation resistance. Currently, the low-temperature densification technology for 3D carbon fibre reinforced UHTCs is relatively scarce, meanwhile the long-term and high-temperature ablation-resistant materials still require further development. Herein, combining with reactive hot pressing at 1800 ℃, the highly dense 3D C f /ZrC-SiC composites were innovatively prepared through cyclic infiltration of slurry into 3D carbon fibre preform. The 3D C f /ZrC-SiC exhibited an excellent ablation resistance under a heat flux of 8.9   MW/m². By regulating the ratio of in situ phases ZrC and SiC, 3D C f /ZrC-SiC had an optimal mass ablation rate of only 0.75   mg/s and an optimal linear ablation rate of only -0.20 μm/s during the ablation process. The excellent ablation resistance was attributed to the formation of a dense ablation layer, which effectively inhibited the matrix from further ablation.