Fabrication of Nb3Al superconductor by the optimized mechanical alloying method with low temperature

- Due to a much better strain tolerance than Nb3Sn, Nb3Al has been considered as an excellent candidate for making high field magnets. At present, the Nb3Al superconducting wires were prepared mainly by the Jelly-roll method combined with a rapid heating and quenching (RHQ) heat treatment at around 2000 °C. In this study, Nb3Al superconductor with Tc of 15.6 K is directly prepared with a mechanical alloying method followed by a low temperature annealing at 800 to 900 °C. Our results hint the possibility that Nb3Al superconducting wire with high performance can be prepared below the melting point of Cu (1080 °C) by a conventional powder in tube (PIT) method, thus effectively avoiding high temperature heat treatment and RHQ device.

Mechanical alloying was used to synthesize Nb3Al superconductor successfully, and the process was optimization under various preparation conditions. In the current study, Nb3Al superconductor with Tc of 15.6 K was directly prepared from high quality Nb (Al) solid solution by mechanical alloying method and heat treatment at a low temperature of 800 to 900 °C. The results showed that Nb3Al superconducting wire with high performance could be prepared after heat treatment below the melting point of Cu (1080°C) and using Nb (Al) solid solution and conventional powder in tube (PIT) method, thus effectively avoiding ultra-high temperature heat treatment and special rapid heating and quenching(RHQ) device.