PRODUCTION METHOD FOR NB₃SN SUPERCONDUCTING WIRE ROD, PRECURSOR FOR NB₃SN SUPERCONDUCTING WIRE ROD, AND NB₃SN SUPERCONDUCTING WIRE ROD USING SAME

摘要

The present invention provides: a Nb₃Sn superconducting wire rod that is produced by the internal tin process and that has a number of useful functions in such aspects as promotion of Nb₃Sn layer generation, mechanical strength (and increase in interfacial resistance) of superconducting filaments, critical temperature (magnetic field), miniaturization of crystal grains, etc.; and a production method therefor. The Nb₃Sn superconducting wire rod production method according to one embodiment of the present invention comprises: a step for providing a rod material 10 which has an alloy composition represented by Cu-xZn-yM (where, x is 0.1-40 mass%; M=Ge, Ga, Mg or Al, provided that x is 0-40 mass% for Mg), and a central part of which is provided with a Sn insertion hole 12, and which has a plurality of Nb insertion holes 14 that are discretely disposed along the outer peripheral surface of the Sn insertion hole 12; a step for installing an alloy bar having an alloy composition of Sn-zQ (Q=Ti, Zr, Hf) in the Sn insertion hole 12, and inserting a Nb core in the Nb insertion holes 14; a step for reducing the diameter of the rod material 10 so as to prepare a Cu-xZn-yM/Nb/Sn-zQ composite multicore wire having a prescribed outer diameter; and a step for subjecting the composite multicore wire to a heat treatment for generating a Nb₃Sn phase.