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

Area of Science:

• Materials Science
• Polymer Chemistry
• Electrical Engineering

Background:

• Simultaneously achieving high dielectric loss, breakdown strength, mechanical shock strength, thermal conductivity, and weight stability in cured potting-adhesive materials for electrical insulation is a significant challenge.
• Epoxy-based materials are widely used but often require enhancement to meet demanding performance criteria.

Purpose of the Study:

• To design and fabricate novel epoxy-based composite potting-adhesives.
• To investigate the effect of inorganic micro-particle fillers (alpha-silica, alpha-alumina, alpha-SiC) on the overall properties of epoxy composites.
• To optimize the composition for enhanced electrical insulation and mechanical performance.

Main Methods:

• Fabrication of epoxy-based composite potting-adhesives using a combination of high- and low-molecular-weight epoxy resins.
• Incorporation of low-cost inorganic micro-particles: alpha-silica, alpha-alumina, and alpha-SiC.
• Heat-induced curing of the resin matrices.

Main Results:

• Silica filler demonstrated superior performance compared to alumina and SiC.
• The silica-filled composite exhibited excellent overall properties, including high breakdown strength (~48 MV/m) and shock strength (~9950 J/m²).
• The large band gap of silica contributed to high breakdown strength and ageing breakdown strength, while its deformation trait enhanced shock strength.

Conclusions:

• Epoxy-based composites filled with alpha-silica micro-particles offer a promising solution for high-performance electrical insulation materials.
• The developed materials exhibit a favorable balance of dielectric, breakdown, mechanical, and thermal properties.
• This research paves the way for the large-scale fabrication of advanced epoxy-based hybrid potting-adhesives.