Study on Preparation, Thermal Conductivity, and Electrical Insulation Properties of Epoxy/AlN

High thermal conductive epoxy composites are particularly suitable for the impregnation process of superconducting power equipment due to their high electrical insulation property and low thermal expansion. In this study, the preparation and impregnation procedures of high thermal conductive epoxy (EP) composites were investigated first. Based on the orthogonal experiment results and the range analysis, the critical factors affecting on the thermal conductivity of final product in sequence were determined as aluminum nitride (AlN) filler content, filling ratio of AlN with different sizes, curing temperature, and surface modification method of AlN fillers. Through investigating the preparation factors of thermal conductive AlN/EP composites on their electrical insulation properties further, it was found that the increase of filler content, addition of nanofillers, and low curing temperature are advantageous for improving the electrical insulation property of composites. This study offers an experimental basis for the preparation and electrical application of dielectric polymer composites with high thermal conductivity in HTS equipment' manufacture.