TiC掺杂12芯MgB2线材微观结构以及超导电性

Microstructure and Superconductivity of TiC-Doped 12-Filament MgB2 Wires

摘要:

采用 PIT工艺，以分步法粉末为装管前驱粉，选用中心铜铌复合棒增强的导体结构制备了TiC掺杂MgB2多芯线材，研究了不同热处理温度对于粉末相组成、线材的微观结构以及超导电性的影响，结果表明分步法粉末能够有效提高C原子的取代水平，同时芯丝中MgB2晶粒尺寸达到亚微米级，MgB2晶粒连结性较好，制备多芯线材在4.2 K，5 T时，其Jc仍高达3×104 A/cm2。

Abstract:

TiC-doped 12-filament MgB2 wires was prepared by PIT method and enhanced by Cu/Nb composite cores. The precursor powder was treated in two steps. The effects of different temperatures on the phase composition, microstructure and superconductivity of the MgB2 wires were studied. Results show that two-step powders can increase the C substitution level effectively, and meanwhile the grain size of MgB2 reaches submicrometer level in the cores. MgB2 grains have good bonding property. The Jc can reach 3×104 A/cm2 when the wires are prepared at 4.2 K, 5 T.