Preparation and ablation properties of SiC modified C/C composites

SiC modified carbon fiber reinforced carbon (C/C) composites were prepared by adding SiC micropowder to the carbon fiber preform before thermal gradient chemical vapor infiltration densification by using an ultrasonic vibration infiltration. The microstructure of composites was studied by X-ray diffraction and scanning electron microscopy. The ablation property of the composites was investigated by using oxyacetylene ablation equipment. The results show that, SiC particles are mainly distributed among the pryocarbons. The linear ablation rate and mass ablation rate of the SiC modified C/C composite are 4.0 × 10^-3 mm/s and 3.19 × 10^-3 g/s while after ablated for 30 s, which were 47.1% and 70.6% of the C/C composite, respectively. The introduction of SiC particles can obviously improve ablation property of the C/C composite, which is attributed to that the addition of SiC particles to C/C composite can effectively prevent oxidation and remedy defects which reduce thermochemical oxidation in the oxygen-acetylene.