Abstract: A method for manufacturing a powder-metallurgy processed Nb3Sn superconducting wire is provided. In the method, a sheath made of Nb or a Nb alloy is filled with a raw material powder containing Sn. The sheath filled with the raw material powder is subjected to diameter reduction to form a wire. The wire is heat-treated to form a superconducting phase at the internal surface of the sheath. The raw material powder is prepared by adding a Sn powder to a Cu—Sn alloy powder or a Cu—Sn intermetallic compound powder, and is compacted under isotropic pressure.

Abstract: A method for fabricating a Nb3Sn superconducting wire includes the steps of loading or inserting a core material containing at least Sn into a pipe member made of Nb or a Nb alloy, inserting the pipe member into a Cu billet to form a composite member, subjecting the composite member to diameter reduction, and then heat-treating the composite member to form a Nb3Sn superconducting layer from the inner surface of the pipe member, wherein, in the pipe member made of Nb or the Nb alloy after the diameter reduction, the average crystal grain size is 0.1 to 2 ?m, and preferably, the total concentration of oxygen, nitrogen, and carbon is 120 ppm or less.

Abstract: A method for producing a copper alloy ingot with suppressed casting defects, segregation of components and lower oxide content comprising heating a copper alloy material in a graphite crucible to melt the copper alloy material. The molten alloy in the graphite crucible is cooled from the bottom of the crucible so that the molten alloy solidifies in a single direction.