Procedure of densifying filaments for a superconductive wire

A method for producing a superconductive wire from an initial element, the completed superconductive wire having one or more superconductive filaments with a diameter between 2 μm and 5 mm which are enclosed in a metallic matrix, the superconducting wire also having at least one highly conductive ohmic element, the method comprising the steps of:

• a) executing a deformation step in which the initial element is subjected to a sequence of swaging, drawing or rolling deformations to form an elongated intermediate element with polygonal cross section;
• b) densifying, following step a), material of the filaments in said intermediate element in one or more high pressure densification steps, the densification steps effecting simultaneous action of at least 4 hard surfaces perpendicular to an axis of the elongated intermediate element, thereby exercising high pressure P≧100 MPa on a part of the intermediate element having an axial length L;
• and
• c) forming, following step b), the superconductive filaments in a reaction heat treatment between 300° C. and 1200° C.