Influence of carbon preform density on the microstructure and ablation resistance of CLVD-C/C-ZrC-SiC composites

In chemical liquid vapor deposition (CLVD) technique, carbon preform density is a crucial factor to control the microstructure of C/C-ZrC-SiC composites, which also determines the ablation resistance. The effects of preform density on the microstructure and ablation behavior of CLVD-C/C-ZrC-SiC composites were studied. Results demonstrated the composites prepared from the preform with a density of 0.91 g/cm³ showed a dense microstructure and proper ceramic content. Under an oxyacetylene flame, the composites displayed an excellent ablation resistance. The good ablation resistance was ascribed to the proper preform density, which promoted the formation of uniform and continuous protective layer of ZrO₂-SiO₂.