Effects of filler distribution and interface thermal resistance on the thermal conductivity of composites filling with complex shaped fillers

The complex shaped fillers are extensive manufactured to replace the conventional spherical filler for their excellent strengthen heat transfer performance. In this study, the effects on the effective thermal conductivity of filled composites are investigated in regard to filler content, complex shape, directional angle and interface thermal resistance. The results indicate that the effect of interface thermal resistance is direct related with the surface area of the filler. The composite with I shaped filler has the largest decrease of effective thermal conductivity that caused by interface thermal resistance, the spherical filler least. The difference between various shaped fillers decrease with interface thermal resistance. However, I shaped and T shaped fillers also have the best performance of enhancing heat transfer in real filled composites. The rectangular and elliptical fillers have great impact on the thermal conductivity only when they are placed along the heat flux direction. The directional angle is a key point for fillers with large ratio of length to diameter. The random filler model is a more accurate way to predict the thermal conductivity of filled composite, and it is highly closed to tested results.