Ablation properties of Cf/C-SiC-MoSi2 composites: Effects of hydrothermal penetration temperature

The effects of hydrothermal penetration temperature on the ablation properties of Cf/C-SiC-MoSi2 composites were studied. With the hydrothermal temperature rising, the distribution depth of ceramics along the cross-section of the composites increased. Meanwhile, the increase in densities and the decrease in porosities of the composites were achieved. When the penetration temperature reached 200 °C, the composites showed the best ablation properties after plasma ablation test for 60 s at 2300 °C. The mass ablation rate was 2.28 mg cm−2 s−1, which decreased by 65%, 54% and 29% compared to composites prepared at 140 °C, 160 °C and 180 °C, respectively. Also the sample prepared at 200 °C showed the lowest linear ablation rate. The increasing depth and amount of ceramics in the composites could provided SiC and MoSi2continuously to prevent the oxidation of carbon, rather than be easily blown away by strong scouring force. The good ablation behavior is attributed to the higher density and amounts of ceramics, the generation of SiO2 and MoO2.