The effects of pore in C/SiC composites on thermal diffusivity and thermal radiation properties were investigated systematically. Pores were introduced into C/SiC by oxidizing carbon phase at 700 °C and damaged the thermal properties of C/SiC composites. Because of little changes in the pore shape and the pore orientation in C/SiC, thermal diffusivity of samples increased linearly with porosity. The pores within C/SiC absorbed and reflected the radiated heat, decreasing spectral emissivity. However, the temperature dependence of spectral emissivity didn’t change by the pore. With measurement temperature increasing, the pores weakened the thermal radiation property of samples gradually. A linear relation was suggested to quantify the negative effect of pores on the total emissivity.

系统研究了C / SiC复合材料中孔隙对热扩散率和热辐射性能的影响。通过在700°C下氧化碳相将孔引入C / SiC，并破坏了C / SiC复合材料的热性能。由于C / SiC中孔的形状和孔取向几乎没有变化，因此样品的热扩散率随孔隙率线性增加。C / SiC中的孔吸收并反射了辐射热，从而降低了光谱发射率。然而，光谱发射率的温度依赖性并未因孔而改变。随着测量温度的升高，孔隙逐渐减弱了样品的热辐射性能。建议使用线性关系来量化孔对总发射率的负面影响。