Microstructure Modeling for Prediction of Thermal Conductivity of Plain Weave C/SiC Composites Considering Manufacturing Flaws

摘要

Utilized photomicrographs taken by scanning electron microscope (SEM), an accurate representative volume element (RVE) model for plain weave C/SiC composites is established. Based on the steady-analysis method, the in-plane and thickness direction thermal conductivity of the C/SiC composites are calculated as 25.6Wm~(-1)K~(-1) and 12.1Wm~(-1)K~(-1), respectively. The manufacturing flaws have different effect on thermal conductivity. Compared with RVE without flaws, the result shows that matrix cracks make thermal conductivity decrease by 7.2% in the in-plane direction and have little effect in the thickness direction; matrix porosities have a significant effect on thermal conductivity, which make the thermal conductivity decrease by 16.7% in the in-plane direction and decrease by 25.4% in the thickness direction. The variation law of thermal conductivity along with porosity volume is also observed: as matrix porosity volume fraction is increasing, the thermal conductivity of material shows significant decrease.