Improvement of Superconducting Properties by Optimized Post-Heat Treatment for Nb3Al Wires Fabricated by RHQ

With extremely high critical current density (Jc) and excellent strain tolerance, Nb
₃
Al superconductor is considered as an alternative to Nb
₃
Sn for application of high-filed magnets. However, complexity in the phase formation of Nb
₃
Al hinders the Nb
₃
Al superconducting wires to satisfy the requirement of engineering applications at present. Here, we have reported the improved performance of simple-structured 18-filamnet jelly-roll Nb
₃
Al precursor long wires fabricated with rapid heating and quenching (RHQ) process. After processed with RHQ heat-treatment under various heating conditions, the Nb
₃
Al wire were post-heat treated at a temperature between 700 °C to 1100 °C. The phase formation and the superconducting properties of the wires were investigated. It has been found that, even if the RHQ process deviates from the optimum processing state, the superconducting properties of the wire can be improved by appropriately selecting post-heat treatment conditions.