Ablation Behavior of Zr–Al(Si)–C Layered Carbides Modified 3D Needled C/SiC Composites

3DN C/SiC composites modified through the combined method of slurry impregnation (SI) with reactive melt infiltration (RMI) can obtain obviously improved mechanical properties. However, when used under the oxyacetylene torch ablation environment, metal melt and low melting point oxides usually lead to the low ablative properties. In this paper, Al₄₀Si₆₀ alloy and Si melt are used to infiltrate 3DN C/SiC preforms impregnated with TiC or ZrC powders, respectively. Large amount of Ti₃Si(Al)C₂ or Zr₃Al₃C₅ (and Zr₃[Al(Si)]₄C₆) with nano-laminated structure generated in the modification matrix, which not only increase the flexural strength of the composites, but also reduce the content of low melting point phases in the modification matrix. These layered carbides can keep steady under air flow, thus further improve material's ablative properties. Meanwhile, during the ablation of Zr–Al(Si)–C layered carbides modify 3D needled C/SiC, the high melting point layered carbides act synergistically with the high melting point ZrO₂ generated. They can block the ZrO₂ generated from migrating along with the air flow, so that ZrO₂ can effectively act its pinning effect on the oxide melt and finally obtain desirable ablative properties.