Comparative investigation exploring the role of carbonization features on the ablation behavior of graphite/phenolic and pitch/phenolic composites

This study examines the influence of carbonization features, char structures and microstructures of graphitic carbon (GC) on the ablation behavior of graphite (G) and pre-oxidized mesophase pitch (OMP) modified boron phenolic (BPR) composites. Results showed that the introduced G and OMP can both effectively hinder the growth of defects, while improve the graphitization degree of residue char during ablation. However, some areas of the ablated surface of GBPRs would randomly splashed at an early stage because of the thermal dimensional stability mismatch between G and matrix. But as the OMP underwent a carbonization process, in company with the resin matrix, the ablated surface of OMPBPRs keep complete and smooth. Therefore, we found that the formation of mosaic combination and the compatibility of co-carbonization process are the keys for enhanced ablation performance. These findings would provide some inspirations for the development of more advanced polymer-matrix ablative composites in the future.