Effect of Heat Treatment Reaction Time on the Performance of MgB2 Wires

MgB
₂
superconductor has the advantages of low cost of raw materials and high critical temperature. Since the MgB
₂
superconductor is easily damaged under strain, the winding and reaction process is preferable when manufacturing MgB
₂
conductors or magnets. Recently, two types of MgB
₂
wires produced by Hyper Tech Research, Inc. and Western Superconducting Technologies Co., Ltd. (WST) were studied in the Institute of Plasma Physics Chinese Academy of Sciences (ASIPP). The heat treatment schedules recommended by the manufacturers of two types of MgB
₂
wires are short. Large-scale conductors and magnets to be manufactured in the future require a longer heat treatment time to conduct heat and even the temperature of each part. Therefore, MgB
₂
conductors and magnets require new optimized heat treatment schedules. The effect of extended reaction time on the performance of two types of MgB
₂
wires was tested. It was found that when the reaction time window for Hyper Tech MgB
₂
wire was kept for 2 h and for WST MgB
₂
wire was kept at 4 h, their critical current did not reduce significantly. The new heat treatment schedule can be applied to MgB
₂
cable-in-conduit conductor (CICC).