Method for producing oxide superconducting wire material, method for modifying oxide superconducting wire material, and oxide superconducting wire material

摘要

A method of manufacturing an oxide superconducting wire according to the present invention comprises a step (S1, S2) of preparing a wire formed by covering raw material powder of an oxide superconductor with a metal (3) and a heat treatment step (S4, S6) of heat-treating the wire in a pressurized atmosphere having a total pressure of at least 1 MPa and less than 50 MPa in the heat treatment. At a heat-up time before the heat treatment in the heat treatment step (S4, S6), pressurization is started from a temperature reducing 0.2 % yield strength of the metal (3) below the total pressure in the heat treatment. Thus, formation of voids between oxide superconducting crystals and blisters of the oxide superconducting wire is suppressed while the partial oxygen pressure can be readily controlled in the heat treatment, whereby the critical current density can be improved.