Significant enhancement of Thermal conductivity in epoxy filled ceramic fillers

Thermal percolation is one of the subjects that have been debated in the literature and there has been no firm conclusion about the point. In order to find out whether thermal percolation is possible in ceramic fillers, high amount of Alumina, i.e., 65% and 70% wt. along with a hybrid system of Alumina (62.5% wt.) and Boron Nitride (BN) (5% wt.) were incorporated in DGEBF. Thermal conductivity (TC) calculations based on thermal diffusivity, density and Cp measurments, showed an increase in TC from 0.324 W/mK for pristine epoxy to 1.966 W/mK for the sample containing 65% wt. of Alumina. The sample containing 70% wt. Alumina, showed a significant increase in TC to the value of 4.741 W/mK which was ascribed to percolation phenomenon. Also using hybrid system, was not as effective as expected in TC enhancement.