METHOD FOR PRODUCING OXIDE SUPERCONDUCTING WIRE MATERIAL, METHOD FOR MODIFYING OXIDE SUPERCONDUCTING WIRE MATERIAL, AND OXIDE SUPERCONDUCTING WIRE MATERIAL

摘要

A method for producing an oxide superconducting wire material which has steps (S1 to S2) of making a wire material having a form in which a raw material powder of an oxide superconducting material is covered with a metal (3) and heat treatment steps (S4, S6) of subjecting the resulting wire material to a heat treatment in a high pressure atmosphere exhibiting a total pressure of 1 MPa or more and less than 50 MPa in the heat treatment, wherein in the temperature rise prior to the heat treatment in the heat treatment steps (S4, S6), a pressuring operation is started at the temperature from which the 0.2 % offset yield strength of the metal (3) becomes less than the total pressure in the heat treatment. The above method allows the formation of interstices between crystals of the oxide superconducting material and the inflation of the oxide superconducting wire material to be inhibited and also allows the easy control of the partial pressure of oxygen during the heat treatment, which results in the improvement of the critical current density of the resultant wire material.