A Study on Thermal Conductivity of Epoxy/Al2O3 Composites

Abstract

The aim of this study is to heighten and examine thermal properties of epoxy based composites using alumina (Al2O3) micro-fillers. This work deals with preparation of epoxy composites with high content of micro-filler (Al2O3) up to 22.1vol. %.Experimental thermal conductivity tests were evaluated in each specimen and compared with the proposed model. This study was mainly focused on alumina particles of spherical shape is an effective way to enhance both thermal conductivity and sufficient voltage endurance. A numerical simulation using finite element package ANSYS is used to explain heat transfer process within epoxy matrix filled with micro alumina and its effective thermal conductivity values is validated with experimental results and theoretical model correlations. It was elucidated that with 11.3 vol% micro-alumina filled epoxy composites in numerical analysis its thermal conductivity is 0.7Wm-1k-1while in experimentation with 22.1 vol% its thermal conductivity is 0.82 Wm-1k-1 which is reasonably higher compared with neat epoxy resin. The results show that theAl2O3 particles show a percolation behavior at this volume fraction (16vol %) at which a sudden jump in the thermal conductivity is noticed. This is the critical concentration at which Al2O3 particles start contacting with each other and hence the actual size of the agglomerates becomes larger.The effect of the filler size, filler loading, and dispersion conditions of the micro-fillers on the glass-transition temperature (Tg) have been studied.