Fabrication of Superconducting Wires by the Mechanical Alloying Method

Although the rapid heating quenching and transformation method has been used as a general way to fabricate high-performance Nb₃Al superconducting wires, the complicated heat treatment apparatus and techniques obstruct its practical application. In this paper, Nb-Al saturated solid solution (Nb(Al)_ss) was fabricated by the mechanical alloying method at room temperature, and the superconducting onset transition temperature (T_c-onset) of the Nb₃Al bulk transforming from the Nb(Al)_ss reached 15.3 K. Based on these results, two groups of Nb₃Al superconducting wires were fabricated in combination with the in situ powder-in-tube method to investigate the effects of ball milling time, wire diameter and the cross-sectional shape on the superconducting properties, and the factors that affected the critical current density (J_c) were also discussed. The best value of J_c in magnetic induction at 6 T was obtained in the round wire with a diameter of Φ1.0 mm fabricated with the powder ball milled for 5 h.