Nano silica modified carbon–phenolic composites for enhanced ablation resistance

High ablation resistant carbon–phenolic (C–Ph) composites were fabricated by the addition of nano silica powder and tested under plasma arc jet at a flux of 2.5 MW m−2. Nano silica C–Ph composites exhibited much higher ablation resistance compared to conventional C–Ph composites under similar conditions. Microstructure and X-ray diffraction studies reveal that nano silica reacts with char at high-temperature, forming ablation resistant silicon carbide phase. The mechanism of in situ siliconization and the thermophysical properties of the C–Ph composites are discussed.