Ultra-high temperature ceramic infiltrated carbon-fibre composites were prepared by precursor infiltration and pyrolysis (PIP) using a laboratory synthesized precursor. Microstructures and thermal properties including thermal expansion, thermal diffusivity, specific heat capacity and oxidative stability are correlated. XRD reveals the presence of C_f-HfC and C_f-HfC-SiC phases without formation of oxides. The CTE observed at 1200 °C is slightly higher for C_f-HfC (3.36 × 10⁻⁶ K⁻¹) compared to C_f-HfC-SiC (2.95 × 10⁻⁶ K⁻¹) composites. Lower thermal diffusivity of the C_f-HfC-SiC compared to C_f-HfC composites is attributed to a thermal barrier effect and cracks in the composites which formed due to the CTE mismatch between carbon fibre and the matrix as well as CO generated during graphitization. The thermal conductivity of C_f-HfC (4.18 ± 0.14 Wm⁻¹ K⁻¹) is higher than that of C_f-HfC-SiC composite (3.33 ± 0.42 Wm⁻¹ K⁻¹). Composites microstructures were coarse with some protruding particles (5 μm) with a homogeneous dense (∼70%) matrix (HfC and HfC-SiC) for both composites.

使用实验室合成的前驱体，通过前驱体渗透和热解（PIP）制备了超高温陶瓷渗透碳纤维复合材料。包括热膨胀，热扩散率，比热容和氧化稳定性的微观结构和热性能是相关的。XRD显示出存在C _f -HfC和C _f -HfC-SiC相而没有形成氧化物。与C _f -HfC-SiC（2.95×10 ^-6  K ^-1）复合材料相比，C _f -HfC（3.36×10 ^-6  K ^-1）在1200°C观察到的CTE稍高。与C _f相比，C _f -HfC-SiC的热扩散率更低-HfC复合材料归因于热障效应和复合材料中的裂纹，该裂纹是由于碳纤维与基体之间的CTE不匹配以及石墨化过程中生成的CO而形成的。C _f -HfC（4.18±0.14 Wm ^-1  K ^-1）的导热系数高于C _f -HfC-SiC复合材料（3.33±0.42 Wm ^-1  K ^-1）的导热系数。复合材料的微观结构是粗糙的，带有一些突出的颗粒（5μm），具有均匀的致密（约70％）基质（HfC和HfC-SiC）。