MgB2 Superconducting Joint Technique Based on Mg Diffusion Method

MgB2, which has a high stransition temperature (Tc) of 40 K, has great potential for superconducting applications. Recently, significant improvements in the performance of MgB2 wires have enabled applications, such as superconducting magnets, magnetic shielding devices, flux transformers, and gradient meters. However, the problem of superconducting joints in some applications must be solved. In this study, low resistance joints between MgB2 wires were fabricated using the Mg diffusion method. The MgB2 wires were inserted into B bulks and compacted to different densities. Liquid Mg was reacted with the B bulk to form MgB2. The impact of the compaction pressure of the B bulk was studied. With the increase of compaction pressure, the Tc of the joint decreased while the critical current (Ic) of the joint increased. The highest Tc value of the joint was 39 K, and the highest Ic value of the joint at 0 T was 51 A at 20 K.