Ablation property and mechanism of three dimensional needled C/(SiC-TaC) composites

Three dimensional carbon fiber reinforced silicon carbide-tantalum carbide (3D C/(SiC-TaC)) composites were fabricated by slurry impregnation combined with chemical vapor infiltration SiC process. The ablation property was investigated by using oxyacetylene ablation equipment. The materials and microstructures of the ablated samples were characterized by X-ray diffraction, energy dispersive spectroscopy and scanning electron microscopy. The linear and mass ablative rates were 0.07 mm/s and 0.096 g/s, respectively. The results indicate that the addition of TaC to C/SiC improves the anti-ablation performance at ultra high temperature. Obvious ablation hole was found in the center region, compact Ta₂O₅ layer covered and protected the carbon fibers and matrix. Sublimation, oxidation and mechanical denudation were the main ablation mechanisms in the center region of composites. Meanwhile, thermochemical oxidation controlled the ablation in the transition and outer regions.