Performance study of a new epoxy resin IR-3 in HTS-based high-field magnet application

Abstract

REBCO (Rare-earth-based barium copper oxide) conductors are appropriate materials for high-field magnet applications. Vacuum impregnation using epoxy resin is a technique widely used for stable operation of superconducting coils. However, epoxy-impregnated REBCO coils often experience critical current degradation problems. Finding a suitable impregnating material for REBCO coils is important for their application in high-field superconducting magnets. A new toughness epoxy, IR-3, was developed recently. An in-depth understanding of IR-3 on the performance of REBCO coils is critically necessary for its application. Thus, this paper explores the effects of IR-3 impregnation on the performance of REBCO coils at 77 K and 4.2 K. The test results are compared to similar coils impregnated with CTD-101 K and MY750. Meanwhile, the radial stresses at 77 K in self-field and 4.2 K under 10 T were simulated. All epoxy impregnated REBCO coils showed no decay in critical current after thermal cycles at 77 K. When charged at 4.2 K in external fields of 5 T and 10 T, the IR-3 impregnated REBCO coils avoided performance degradation problems and had superior electrical stabilities. Combing the excellent performance at low temperatures, IR-3 is a promising candidate material for impregnating high-field REBCO coils.

3D numerical investigation on delamination behavior of the epoxy impregnated REBCO pancake coil

“…Because the tensile radial stress is mainly caused by the thermal expansion coefficient (CTE) mismatch between the REBCO CC and the epoxy resin layer in the epoxy impregnated REBCO pancake coil. In this regard, the investigation showed that the thermal stress can be reduced by modifying the CTE of the epoxy resin by adding fillers to the epoxy resin [38][39][40][41]. Meanwhile, the overband fabrication technology is also widely used in the epoxy impregnated REBCO pancake coil or no-insulation REBCO coil to reduce the radial and hoop stresses [42][43][44].…”

The Numerical Analysis of Force and Comparison of Pulse Magnet and Electromagnetic Forming Coil

“…The interlayer reinforcement material of the coil conductor generally Materials 2023, 16, 5828 2 of 12 uses Zylon, and the outer layer reinforcement uses glass fiber [7]. Finally, the whole coil is reinforced with epoxy resin and fixed [8]. The forming coil adopts the reinforcement technology of the pulse magnet to improve the overall strength.…”