A quench-age method for the fabrication of Nb(Al) superconductors

The possibility of taking advantage of the extended, high temperature solid solubility of Al in Nb in order to produce composite Nb-Nb3Al superconductors was investigated. Rapid quenching after an elevated (1950°C) solution treatment makes it possible to retain at room temperature a metastable solid solution containing up to 21 at.% Al. The solid solution transforms into the A-15 phase in the course of a short and relatively low temperature(1000°C) aging treatment. The inductively measured onset of superconductivity was 17.6 K in a 100 μm thick core of Nb3Al embedded in a Nb matrix and prepared by the quench-age method.