High-performance ceramic/epoxy composite adhesives enabled by rational ceramic bandgaps

High over-all properties, including low dielectric loss, high breakdown strength, high mechanical shock strength, high thermal conductivity and high weight stability, are very difficult to simultaneously achieve in electrical-insulation applicable cured potting-adhesive materials. To deal with this challenge, in this work, we have designed and fabricated a series of epoxy based composite potting-adhesives filled with low-cost and high-performance inorganic micro-particles including alpha-silica, alpha-alumina and alpha-SiC. Combination employment of high-molecular-weight and low-molecular-weight epoxy resins as matrices has been made. Heat-induced curing or crosslink of resin matrices has been carried out. Large band gap of silica filler has endowed the cured composite with high breakdown strength and ageing breakdown strength, and meanwhile relatively high deformation trait of silica has led to high shock strength of cured composite. Silica filler has been found to be superior to other two fillers, namely, optimal over-all properties such as dielectric, breakdown, mechanical and thermal features have been obtained in silica filled cured composite. High breakdown strength of ~48 MV m(−1) and shock strength of ~9950 J m(−2) have been achieved in silica loaded composite. This work might open up the way for large-scale fabrication of promising epoxy-based hybrid potting-adhesives.