2.5D C/SiC复合材料的热物理性能

Thermophysical Properties of 2.5D C/SiC Composites

分别采用热膨胀仪和激光脉冲导热仪测试2.5D C/SiC复合材料从室温到1400℃纵向、横向的热膨胀系数和厚度方向的热扩散系数。结果表明,2.5D C/SiC复合材料的热膨胀系数随温度的升高而缓慢升高,在350℃和700℃附近出现波动,且横向的热膨胀系数略高于纵向。热扩散系数随温度的升高逐渐降低,且下降速率随温度的升高而变缓。CVD SiC涂层后,材料热扩散系数提高1～2倍。

The coefficients of thermal expansion and thermal diffusivity of the 2.5D carbon/silicon carbide composites tested from room temperature to 1400℃ by the thermal dilatometer and laser flash apparatus. The results showed that the coefficient of thermal expansion increased slowly as temperature increased, with fluctuations at 350℃ and 700℃, and the transverse coefficient was slightly higher than the longitudinal coefficient. However, the coefficient of thermal diffusivity decreased as temperature increased, and the rate of decline turned slower. The coefficient of thermal diffusivity of the composite with SiC coating increased by 1 - 2 times compared to the material without SiC coating.