Influence of precursor content on the microstructure and ablative resistance of CLVD-C/C-SiC-ZrC composites

Precursor content is a key to control ablation resistance of CLVD-C/C-SiC-ZrC composites. The ceramic content of the composites prepared with 20 wt% precursor was only 8.38 vol%, so an oxide protective coating was not formed. High-content precursors promoted the formation of oxide coating, especially the composites prepared with 50 wt% precursor had a complete oxide coating. Thus, mass and line ablation rates were only 0.64 mg/s and 0.45 µm/s. When precursor content was 65 wt%, the composites had high-content ceramics, but porosity was great and many pores and cracks acted as channels for oxygen diffusion, causing a poor ablation resistance.