Analysis and Optimization of Impregnation Material Parameters for Superconducting Coils

High-field magnets fabricated from Rare Earth-Barium-Copper-Oxide (REBCO) coated conductor (CC) tapes have substantial prospects across diverse application domains. The impregnation process is frequently employed to enhance the mechanical structure stability of superconducting magnets. However, impregnation can lead to damage, such as degradation of critical current (I-c). In this study, a three-dimensional multilayer delamination finite element (FE) model for REBCO CC tape is developed to investigate the impact of impregnation material parameters on damage behavior during the cooling process. Firstly, the accuracy of the established FE model and the feasibility of damage analysis were verified. Then the relationship between damage and I-c is established based on experimental data. It was found that when the normalized I-c degraded to 95%, the normalized damage area caused by both thermal and mechanical stresses was 0.22. Finally, after decoupling and analyzing the influence of each impregnation material parameter on the damage behavior of REBCO tape, the optimization direction of the impregnation material parameters is given from four aspects: material thickness, coefficient of thermal expansion, cohesive strength, and structural strength.