US Patent 7459031 Method for producing Nb

A method for producing an Nb3Sn superconductive wire material using a powder process is provided, in which a powdered raw material is filled in a sheath made of Nb or an Nb-based alloy, and the above sheath is subjected to diameter reduction to form a wire, followed by heat treatment to form a superconducting layer at the interface between the sheath and the filled powder. The above powdered raw material contains powdered Sn, powdered Cu, and a powdered alloy or a powdered intermetallic compound, which is formed from Sn and at least one metal selected from the group consisting of Ti, Zr, Hf, V, and Ta.