Long-term ablation behavior and mechanisms of 2D-Cf/ZrB2-SiC composites at temperatures up to 2400 °C

Long-term ablation behavior and mechanisms of 2D-C-f/ZrB2-SiC composites are studied by air plasma test at temperatures up to 2400 degrees C. After ablation at temperatures lower than 1800 degrees C for 60 s, a porous SiO2 layer forms on the sample surface, which turns to a continuous ZrO2-SiO2 glassy layer at higher temperatures (2000-2400 degrees C). As ablation temperature increases and ablation time extends, ZrO2 grains are precipitated from the ZrO2-SiO2 glass, further coarsening and sintered via a quasi-liquid phase assisted route, finally form a dense ceramic layer. Consequently, the 2D-C-f/ZrB2-SiC composites show a superior anti-ablation property even at 2400 degrees C for 300 s.