Ablation behaviour and mechanical performance of ZrB2-ZrC-SiC modified carbon/carbon composites prepared by vacuum infiltration combined with reactive melt infiltration

• C/C-ZrB2-ZrC-SiC composites fabricated by vacuum infiltration combined with reactive melt infiltration exhibit higher ceramic content and more uniform distribution compared to traditional RMI C/C-ZrC-SiC. • The mass and linear ablation rates of the modified composites are reduced by 68.9% and 29.7%, respectively, relative to C/C-ZrC-SiC. • Improved ablation resistance is attributed to heat removal by B2O3 volatilization and the formation of a continuous ZrO2-SiO2 protective layer that hinders oxygen infiltration. • The novel fabrication method offers a more efficient and cost-effective route for producing high-performance C/C-UHTC composites for aerospace applications.