Single- and multi-core MgB₂ wires have been fabricated by an internal Mg diffusion (IMD) process. Wires uniformity after drawing and/or rolling deformation has been studied by optical microscopy and x-ray micro-tomography. Several short samples taken lengthwise between both ends of the wire were annealed and their critical current measured. It was found that I _c of the single-core barrier-free MgB₂/Fe wire with high fill factor (32.5% of MgB₂) vary by 100% towards the averaged I _c. Multi-core wire having ∼15.0% of MgB₂ and Cu outer sheath shows better uniformity with 25% deviation of I _c over the 10 m length, which is still quite low and needs some improvements. It is expected, that improved in-length uniformity can be reached only for filamentary IMD wires with optimized deforming process and mechanically stronger outer sheath.

单芯和多芯 MgB ₂线已通过内部镁扩散 (IMD) 工艺制造。拉拔和/或轧制变形后的线材均匀性已通过光学显微镜和 X 射线显微断层扫描进行了研究。对导线两端纵向截取的几个短样品进行退火，并测量它们的临界电流。据发现，我 _Ç单芯无障碍-MGB的₂ / Fe的金属丝具有高填充系数（MGB 32.5％₂）由100％改变朝向平均我 _Ç。具有约 15.0% MgB ₂和 Cu 外护套的多芯线显示出更好的均匀性，I _c偏差为 25%超过 10 m 的长度，仍然很低，需要一些改进。预计只有具有优化变形工艺和机械强度更高的外护套的丝状 IMD 线才能达到改进的长度均匀性。