Morphology and anti-ablation properties of PIP Cf/C-SiC composites with different CVI carbon content under 4.2 MW/m2 heat flux oxy-acetylene test

In this work, the needled carbon fiber preforms were used to make seven groups of carbon/carbon composite billets with different matrix carbon contents by controlling the processing time of chemical vapor infiltration (CVI). Cf/C-SiC composites were prepared by infiltration of SiC into these C/C composites billets using poly-carbosilane (PCS) through precursor infiltration and pyrolysis (PIP). After oxy-acetylene torch testing (heat flux of 4.2 MW/m(2)) for 200s, 300s and 400s, respectively, it revealed that the anti-ablation properties of the C-f/C-SiC composite samples were enhanced by a higher content of SiC matrix. Additionally, specimens bearing longer duration tests showed a trend of lower average ablation rates. The lowest linear ablation rate is 0.008 mm/s and the mass ablation rate is 0.0019 g/s for those high SiC content samples tested for 400s. The SEM images of the tested samples showed the mechanism and the non-linear process of ablation resistance progression.

Automated summary

The study used needled carbon fiber preforms to make carbon/carbon composite billets with varying matrix carbon contents through CVI processing time control. Cf/C-SiC composites were then prepared by infiltrating SiC into these billets using PCS. Results showed that higher SiC content led to improved anti-ablation properties, with longer duration tests exhibiting lower ablation rates.SEM images of tested samples illustrated the mechanism and non-linear progression of ablation resistance.