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

Abstract

The aim of this paper is to propose a microstructure modeling for prediction of thermal conductivity of plain weave C/SiC fibre bundles considering manufacturing flaws. Utilized photomicrographs taken by scanning electron microscope (SEM), an accurate representative volume element (RVE) model for carbon fiber bundles is established. Based on the steady-analysis method, the axial and transverse thermal conductivity of the carbon fibre bundles are calculated as 40.32Wm-1K-1 and 11.33 Wm-1K-1, respectively. The manufacturing flaws have different effects on thermal conductivity, the study shows that class A porosity has a significant effect on thermal conductivity, which leads to the thermal conductivity on the axial direction decrease by 13.31% and transverse direction decrease by 20.56% compared with no flaws RVE. While class B porosity has little influence on the k-value. The change law of axial and transverse thermal conductivity along with porosity volume is also observed: as porosity volume fraction is increasing, the thermal conductivity of fibre bundles shows significant linear decrease.

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

“…Plain weave C/SiC RVE consists of fibre bundle, SiC matrix and flaws. The in-plane and thickness direction thermal conductivity of the fibre bundles [8] are already calculated as 40.32 Wm -1 K -1 and 11.33Wm -1 K -1 , and the thermal conductivity of SiC matrix and air are listed in Table 1. The thermal conductivity is changing as the temperature is fluctuating in reality.…”

“…In order to establish an accurate RVE model, internal defects of materials require for quantitative analysis. Analysis shows that class B matrix porosities take 8.1% of the whole material section; class A matrix cracks are perpendicular to the fiber bundles [8] and throughout the matrix, whose mean spacing is calculated as 267.84µm.…”