SiC nanowires/pyrocarbon (SiCnws/PyC) core-shell structure toughened C/C-ZrC-SiC composites were fabricated by CLVD process, and the influences of PyC shell thickness on the microstructure and ablation resistance of the composites were researched. The results presented that SiCnws/PyC core-shell structure had a linear shape, and the composites became dense with the increasing PyC thickness. When the thickness of PyC shell increased from 0 to 2.4 μm, the density and thermal conductivity of the composites was improved gradually, but the coefficient of thermal expansion (CTE) decreased firstly and then increased. After the ablation test for 90 s, the ablation rates of the composites decreased continuously as the PyC thickness increased from 0 to 1.4 μm, but increased when the PyC thickness was up to 2.4 μm. Especially when the PyC thickness was 1.4 μm, the linear and mass ablation rates of the composites were 71.25% and 63.01% lower than those of the composites without PyC shell. The reasons behind the remarkable improvement of anti-ablation property were that the proper PyC thickness could alleviate the CTE mismatch to promote the formation of complete oxide coating, improve the thermal conductivity to reduce heat corrosion and enhance the capability to limit the mechanical erosion.

采用CLVD工艺制备了SiC纳米线/焦碳（SiCnws / PyC）核壳结构增韧的C / C-ZrC-SiC复合材料，研究了PyC壳厚度对复合材料显微组织和耐烧蚀性能的影响。结果表明，SiCnws / PyC核-壳结构呈线性形状，随着PyC厚度的增加，复合材料变得致密。当PyC壳的厚度从0增加到2.4μm时，复合材料的密度和导热率逐渐提高，但热膨胀系数（CTE）先降低然后升高。经过90 s的消融测试后，随着PyC厚度从0增至1.4μm，复合材料的消融速率持续降低，但当PyC厚度增至2.4μm时，消融速率会增加。特别是当PyC厚度为1。4μm时，复合材料的线性和质量烧蚀率比没有PyC壳的复合材料低71.25％和63.01％。抗烧蚀性能显着改善的原因在于，适当的PyC厚度可以缓解CTE失配，从而促进形成完整的氧化物涂层，提高热导率以减少热腐蚀并增强限制机械腐蚀的能力。