Research Progress of Epoxy-Based Composites for Insulating Encapsulation of Superconducting Magnets

Epoxy-based composites are crucial insulating and structural materials for superconducting magnets, providing mechanical strength, winding fixation, and heat transfer. However, future superconducting devices with higher integration and power will place even higher demands on their toughness, thermal conductivity, electrical insulation, and radiation resistance at low temperatures. Otherwise, problems such as cracking, detachment, and low heat dissipation efficiency will arise, which may lead to quenching of low-temperature superconductors (Nb3Sn, NbTi) and a decline in the performance of high-temperature superconductors (YBCO). Research focuses on summarizing the recent progress in modifying epoxy resin to address these issues. The current strategies include formula optimization using mixed curing and toughening agents to enhance mechanical properties, incorporating functional fillers to improve cryogenic thermal conductivity and reduce the coefficient of thermal expansion. Studies also evaluate cryogenic electrical insulation performance (DC breakdown strength, flashover voltage) and radiation resistance under cryogenic conditions. These advancements aim to develop reliable epoxy composites, ensuring the stability and safety of superconducting magnets in applications such as particle accelerators and fusion reactors.