Thermal conductivity measurements of nano-particle-filled epoxies

Abstract

Abstract For conduction-cooled superconducting magnets to be truly effective, it is necessary to have good thermal conduction from the cooling source through the insulating epoxy resin to the magnet winding. We have developed epoxy resins filled with thermally conductive nanoparticles that have significantly increased thermal conductivities while retaining most of their dielectric and mechanical strengths. Base resins, including CTD101K, were filled with alumina, aluminum nitride, or diamond nanoparticles. A wire-based 3ω method was developed to measure the thermal conductivity of the nano-filled epoxies over the temperature range from 4 K to 300 K. A unique aspect of this experimental setup is the 10 μm diameter Invar wire heating element, which serves as a sensitive thermometer down to 4 K. Measurements show the filled resins have improved thermal conductivity, especially at temperatures of 15 K and higher.