Properties of rapid heating, quenching, and transformation (RHQT)-treated powder-in-tube (PIT) Nb₃Al_1−xSn_x wires are studied herein. After the RHQ process, the body-centered cubic (bcc) phase is formed in the Sn-doped Nb₃Al wires. The transformed superconducting A15 phase shows a uniform microstructure and homogenous component distribution feature. With the increase of the Sn doping level, the critical transition temperature (T_c), critical current density (J_c), and irreversibility field (B_irr) of the superconducting wires increase first and then reduce, achieving the highest T_c value of 17.6 K and the smallest ΔT_c of 0.6 K in the 4% Sn doped Nb₃Al wire. The 4% Sn addition helps to improve the layer J_c of the sample to 2.1 × 10⁵ A cm⁻² at 8 K and 5 T, which is about 2.5 times that of the pure Nb₃Al sample. Furthermore, the Nb₃Al_1−xSn_x (x = 0.04) wire gives the highest B_irr value of 17.22, 13.23, and 9.11 T at 8, 10, and 12 K, respectively. The addition of Sn helps to achieve stoichiometric Nb₃Al A15 phase and formation of precipitations with the size of 10 nm, which might act as the flux-pinning center.

中文翻译：

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快速加热淬火相变 (RHQT) 管内粉末掺锡 Nb3Al 线材的显微组织和超导性能

本文研究了快速加热、淬火和相变 (RHQT) 处理的管内粉末 (PIT) Nb ₃ Al _{1- x} Sn _x线材的特性。在RHQ工艺之后，体心立方(bcc)相在Sn掺杂的Nb ₃ Al线中形成。转变后的超导 A15 相显示出均匀的微观结构和均匀的成分分布特征。与Sn的掺杂水平的增加，临界转变温度（Ť _Ç），临界电流密度（Ĵ _Ç）和不可逆场（乙_IRR超导线材先增加后降低的），达到最高Ť _Ç在 4% Sn 掺杂的 Nb ₃ Al 线中，17.6 K 的值和0.6 K的最小 Δ T _c。添加 4% Sn 有助于将样品的层J _c在 8 K 和 5 T下提高到 2.1 × 10 ⁵  A cm ^-2，大约是纯 Nb ₃ Al 样品的2.5 倍。此外，Nb ₃ Al _{1- x} Sn _x ( x  = 0.04) 焊丝在 8、10 和 12 K 下分别提供了_{17.22、13.23}和 9.11 T的最高B _irr值。添加 Sn 有助于实现化学计量的 Nb ₃Al A15 相和尺寸为 10 nm 的析出物的形成，可能作为磁通钉扎中心。