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

Abstract

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-1K-1 and 12.1Wm-1K-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.

Effect of initial density on thermal conductivity of new micro‐pipeline heat conduction C/SiC composites

“…Two‐dimensional C/SiC composites have attracted increasing interests in recent years due to their low densities, high specific strengths, 1 elevated specific module, 2 and noncatastrophic mode of failure, 3 which made them promising thermal structural materials for applications in aerospace, aircraft braking, and space detection 1,4,5 . However, these harsh environments require them possessing not only thermal structural performances like load resistance, 2 but also functional properties such as high thermal conductivity, especially in thickness direction of the composites (about 5‐12 W·m −1 ·K −1 for now) 6‐9 . Therefore, C/SiC composites cannot serve as a functional materials for aerospace vehicle thermal discharge and active cooling of ramjet combustion chamber but a thermal structural materials.…”

Experimental Investigation of the Anisotropic Thermal Conductivity of C/SiC Composite Thin Slab

“…Thermal conductivity 𝜆 is essential for evaluating the heat transfer performance of composites. [19,20] Many works have been conducted to predict the anisotropic thermal conductivity 𝜆anisotropic of C/SiC composites numerically, [21][22][23][24] and yet the corresponding experimental studies at high temperature are rarely reported. For the studies of the measurement of the 𝜆 out-of-plane , Zhang et al [11,12] obtained the out-of-plane thermal diffusivity 𝑎 out-of-plane of 2D plain woven C/SiC composite using a laser flash analysis (LFA) method within the temperature range of 100-500 ∘ C. Cai et al [13] measured the 𝑎 out-of-plane of 3D C/SiC composite over a temperature range from 25 ∘ C to 1300 ∘ C by adopting the LFA method, and the 𝜆 out-of-plane was obtained by measuring its specific heat capacity and density simultaneously.…”