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结合连续管线成型技术和粉末套管方法,原位掺杂SiC制备出了20m长的单芯MgB2/Fe、MgB2/Nb/Fe线材和7芯、19芯及49芯的MgB2/Nb/Cu/Fe复合多芯线材。采用XRD和SEM分别对烧结后样品芯部进行相成分和微观结构研究,并通过TEM对SiC掺杂的机理进行了简单分析。采用四引线法对线材进行电流测量并获得临界电流密度。结果表明,线材经过不同温度保温15min的真空退火后,在800℃形成的MgB2相含量最高,其中单芯MgB2/Fe线材在4.2K,11T下Jc值超过104A/cm2,7芯复合线材在4.2K,7.5T下Jc值也达到104A/cm2,并且具有较好的热稳定性,在低场下仍可稳定通过电流。
A series of MgB2 / Fe and MgB2 / Nb / Fe single wires with length of 20m and MgB2 / Nb / Cu / Si wires with 7, 19 and 49 cores were prepared by in-situ doping of SiC with continuous pipeline forming technology and powder casing method. Fe composite multi-core wire. The phase composition and microstructure of the sintered core were investigated by XRD and SEM. The mechanism of SiC doping was analyzed by TEM. A four-lead method was used to measure the current of the wire and obtain the critical current density. The results show that the content of MgB2 phase formed at 800 ℃ is the highest after vacuum annealing for 15min at different temperatures. The Jc value of single-core MgB2 / Fe wire at 4.2K, 11T exceeds 104A / cm2. K, Jc value of 7.5T also reached 104A / cm2, and has good thermal stability, can still be stable in the low field through the current.