PRODUCTION OF NB3SN SUPERCONDUCTIVE WIRE

摘要

PURPOSE:To obtain a fine Nb3Sn superconductive wire having multi-cored structure by subjecting a small-sized ingot which contains less segregation and impurities and has excellent workability to cold working and aggregating many sets of many assemblies of such worked materials and Sn (alloy) thereby constituting the composite body equiv. to a large-sized ingot. CONSTITUTION:Many pieces of the Nb bodies coated with Cu are aggregated and the Cu-Nb alloy ingot having a prescribed outside diameter and length is formed by a consumable electrode arc melting method using a water-cooled Cu casting mold. Such ingot is subjected to facing then to swaging and drawing to obtain a wire. The wire is then rolled. A rod 1 having the construction in which the wire provided with a through-hole in the central part of the wire having a regular hexagonal shape section is bisected on the plane inclusive of the median axis is formed. The rod 1 is then subjected to a heat treatment at about 950 deg.C in a vacuum and thereafter an Sn rod 2 is disposed in the central part of a pair of the aggregated materials 1, 1' by which the assembly 3 having the regular hexagonal section is obtd. The many assemblies 3 are aggregated and are housed into an Nb pipe and after a Cu pipe is put onto said pipe, the assembly is subjected to cold drawing and heat treatment. The Nb3Sn superconductive wire is thus obtd.