Thermal Conductivity Prediction of SiC/Silicone Rubber Composites Using Combined Separate Axis Theorem-Finite Element Model

The suitable filling scheme is an important factor that affects the thermal conductivity of composites used for heat dissipation. In this study, the separation axis theorem (SAT) is conducted to study the prediction model of the effective thermal conductivity (ETC) of SiC/silicone rubber composites. Based on the representative volume element (RVE) model, a series of cubic units with built-in cubic particles of log-normal distributed size are developed for the SiC/silicone rubber composites. Combined with SAT for contact detection and thermal resistance network theory, a general solution for the ETC of a typical RVE is then derived. Furthermore, ETC prediction models of SiC/silicone rubber composites with filling particles of three typical connection mechanisms are obtained by comparing the experimental data and finite element simulation results. Finally, the thermal conductivity prediction model from this study demonstrated an average reliability of 96.8% which is better than that of the commonly used Maxwell prediction model. This model could be used to predict the ETC and guide the preparation of SiC/silicone rubber composites.