水氧腐蚀环境对2D C/SiC热扩散性能的作用机制研究

通过对不同温度条件下,水氧腐蚀前后2D C/SiC复合材料热扩散性能的演变规律,研究了环境损伤对C/SiC复合材料热扩散性能的作用机制。在水蒸气和氧气混合环境下,C/SiC复合材料内部气孔率增加,同时在材料表面有氧化物形成。材料内部出现的气孔,阻断了热流在材料内部的传输,使得热扩散性能呈现出直线下降的趋势。氧化物的形成,在一定程度上封填裂纹,有助于热量的传输,能够在一定程度上改善材料热扩散性能。

Effect of water vapor and oxygen corrosion environment on thermal diffusivity of 2D C/SiC composites

The effect of environmental corrosion on thermal diffusivity of 2D C/SiC composites is investigated by the microstructural evolution of water vapor and oxygen corrosion under the conditions of different temperatures. In the water vapor and oxygen mixture environment, the porosity increases and the oxide forms in the composites. The pores inside the composites interrupts the heat flow transmission, which results in almost linear reduction of thermal diffusivity of composites. The oxide forming at high corrosion temperature fills up the matrix cracks, which is conducive to thermal transmission and can improve the thermal diffusivity in the composites.