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

The development of advanced aircraft relies on high performance thermal-structural materials, and carbon/carbon composites (C/C) composited with ultrahigh-temperature ceramics are ideal candidates. However, the traditional routes of compositing are either inefficient and expensive or lead to a non-uniform distribution of ceramics in the matrix. Compared with the traditional C/C-ZrC-SiC composites prepared by the reactive melt infiltration of ZrSi2, C/C-ZrB2-ZrC-SiC composites prepared by the vacuum infiltration of ZrB2 combined with reactive melt infiltration have the higher content and more uniform distribution of the introduced ceramic phases. The mass and linear ablation rates of the C/C-ZrB2-ZrC-SiC composites were respectively 68.9% and 29.7% lower than those of C/C-ZrC-SiC composites prepared by reactive melt infiltration. The ablation performance was improved because the volatilization of B2O3, removes some of the heat, and the more uniformly distributed ZrO2, that helps produce a ZrO2-SiO2 continuous protective layer, hinders oxygen infiltration and decreases ablation.