【摘要】 采用 Nb 管富 Sn 法制备 Nb₃Sn 导体母材中添加适量合金元素 Ti 或 Mg 分别显著提高导体在≥12T 或≤12T 磁场区域的载流能力.由于 Ti 和 Mg 改善 Nb₃Sn 材料载流能力的机制不同,同时,Ti 进入 A15型（Nb,Ti）₃Sn 化合物晶格,并占据 Nb 原子的结晶学位置,而进入 Nb₃Sn 反应层的 Mg 则以 Mg-Nb-O 化合物沉淀相微粒弥散分布在 Cu-Sn-Mg 母材侧的 Nb₃Sn 晶粒中,因此,若在母材中同时添加合金元素 Ti 和 Mg 将可能明显提高导体在8—20T 整个实用磁场区域的载流能力.使用（Nb,Ti）₃Sn 导体(0.99mm^?×1.69mm^ω)制造的超导磁体（2a₁×2a₂×2b=31.5mm×70mm×99.5mm）在10.4T NbTi-Nb₃Sn 背景磁场下,磁体工作电流 I_a=392A（未失超）时,磁体中心场强 H_?=14.2T,此时,导体的工作电流密度 Ja（non cu）（14.2T,4.2K）=5.2×10⁴Acm^-2.更多还原

【Abstract】 Adequate addition of Ti or Mg to the matrix have greatly increased the Jc (non Cu) of NbaSn conductor fabricated by Nb-tube Sn-rich method in field region of ≥12T or ≤12T respectively.Because for the mechanism of Ti to increase the Jc (non Cu) of NbsSn conductor is different from that of Mg,and Ti enters the A15 NbaSn lattice and occupies the sites of the Nb atoms,While the Mg additive,in the form of Mg-Nb-O precipitated compound particles,is well-distributed in NbaSn grains near the side of Cu-Su-Mg matrix,it is supposed that simultaneous addition of Ti and Mg to the matrix would obviously increase the Jc (non Cu) of Nb3Sn conductor in the whole practicle field region (8-20T).In 10.4T NbTi-Nb3Sn back-field the centre field Hoo of the magnet (2a1×2a2×2b=31.5mm×70 mm*×99.5 mm) wound by (Nb,Ti)3Sn conductor (0.99 mmt×1.69mmw) reachs 14.1T when the applied current of the magnet Ia is 392A (no quench) and,correspondingly,the applied current density of the conductor Jc (non Cu,4.2 K) is about 5.2×104A cm-2更多还原