Cables including conductors formed form ultra-conductive copper wires which have a lower temperature coefficient of resistance are disclosed. Methods of making the cables including conductors with ultra-conductive copper wires are further disclosed.

A wire (10) is disclosed. Said wire (10), when viewed in cross-section, has at least one first portion (12) and at least one second portion (14) that are interconnected by a third portion (16) in which the wire (10) has a reduced cross-section.

The purpose of the present invention is to provide a method for causing sufficient deformation in precursor particles even when a soft high-purity metal is used for an outer layer material in mechanical milling, and manufacturing an MgB.sub.2 superconducting wire. A method for manufacturing an MgB.sub.2 superconducting wire in which an MgB.sub.2 filament is covered by an outer layer material, the method comprising: subjecting magnesium powder and boron powder to a shock that is insufficient for MgB.sub.2 to be clearly produced, and producing precursor particles in which boron particles are dispersed inside a magnesium matrix; filling a metal tub with the precursor particles; processing the metal tube filled with precursor particles to form a wire; and heat-treating the wire to synthesize the MgB.sub.2; wherein the method is characterized in that a portion of the wire-drawing step includes swaging.

A process to fabricate ultra-fine grain metal wire, comprising: inserting a plurality of metal strands into a flexible elastic polyurethane sheath having an accommodating slot for each of the strands of metal to form a sheathed strand assembly; equal channel angular pressing (ECAP pressing) the sheathed strand assembly through an ECAP die having a plurality of die channels corresponding to the plurality of metal strands. The process is designed to improve electric conductance and mechanical properties of elongated metal parts and is especially applicable to optimize the conductance and tensile strength of copper cables, wires, strings, and rods.

Provided is a medical wire including: a main wire-strand portion that is formed of a plurality of main wire strands and that extends over the entire length of the medical wire; and at least one sub wire-strand portion that is disposed at an outer circumference of the main wire-strand portion, that is secured to the main wire-strand portion, and that is formed of a sub wire strand, wherein the diameter of the sub wire strand is at least twice the diameter of the main wire strand, and a first region having a relatively small lateral cross-sectional area and a second region having a lateral cross-sectional area that is greater than that of the first region are included.

An aluminum alloy wire is composed of an aluminum alloy. The aluminum alloy contains equal to or more than 0.005 mass % and equal to or less than 2.2 mass % of Fe, and a remainder of Al and an inevitable impurity. In a transverse section of the aluminum alloy wire, a surface-layer crystallization measurement region in a shape of a rectangle having a short side length of 50 m and a long side length of 75 m is defined within a surface layer region extending from a surface of the aluminum alloy wire by 50 m in a depth direction, and an average area of crystallized materials in the surface-layer crystallization measurement region is equal to or more than 0.05 m.sup.2 and equal to or less than 3 m.sup.2.

Disclosed is a method of manufacturing a fine wire suitable for speedy and small quantity production of a fine wire having a desired cross-sectional area at low cost without being restricted much by a material. The method includes: stacking a metal powder on an upper surface of a molding plate in which a plurality of semicircular molding grooves are formed in parallel; melting the metal powder by projecting a laser beam onto the metal powder stacked on the upper surface of the molding plate, wherein the laser beam is projected along the molding grooves to melt the metal powder; and removing the remaining metal powder when the melted metal powder is solidified so that a wire is formed in the molding grooves of the molding plate.

Ultra-conductive wires having enhanced electrical conductivity are disclosed. The conductivity of an ultra-conductive wire is enhanced using cold wire drawing and annealing. Methods of making the ultra-conductive wires are further disclosed.

An aluminum alloy wire is composed of an aluminum alloy. The aluminum alloy contains equal to or more than 0.005 mass % and equal to or less than 2.2 mass % of Fe, and a remainder of Al and an inevitable impurity. In a transverse section of the aluminum alloy wire, a surface-layer crystallization measurement region in a shape of a rectangle having a short side length of 50 m and a long side length of 75 m is defined within a surface layer region extending from a surface of the aluminum alloy wire by 50 m in a depth direction, and an average area of crystallized materials in the surface-layer crystallization measurement region is equal to or more than 0.05 m.sup.2 and equal to or less than 3 m.sup.2.

Methods for producing a multifilament Nb.sub.3Sn superconducting wire having a Jc value of at least 2000 A/mm.sup.2 at 4.2 K and 12 T by a) packing a plurality of Cu encased Nb rods within a first matrix which is surrounded by an intervening Nb diffusion barrier and a second matrix on the other side of the barrier remote from the rods thereby forming a packed subelement for the superconducting wire; b) providing a source of Sn within the subelement; c) assembling the metals within the subelement, the relative sizes and ratios of Nb, Cu and Sn being selected such that (i) the Nb fraction of the subelement cross section including and within the diffusion barrier is from 50 to 65% by area; (ii) the atomic ratio of the Nb to Sn including and within the diffusion barrier of the subelement is from 2.7 to 3.7; (iii) the ratio of the Sn to Cu within the diffusion barrier of the subelement is such that the Sn wt %/(Sn wt %+Cu wt %) is 45%-65%; (iv) the Cu to Nb local area ratio (LAR) of the Cu-encased Nb rods is from 0.10 to 0.30; (v) the Nb diffusion barrier being fully or partially converted to Nb.sub.3Sn by subsequent heat treatment; and (vi) the thickness of the Nb diffusion barrier is greater than the radius of the Nb portions of the Cu encased Nb rods; and d) assembling the subelements in a further matrix and reducing the assemblage to wire form such that (i) the multifilamentary Nb.sub.3Sn superconducting wire is formed of a plurality of the subelements, each having a Nb diffusion barrier to thereby form a wire having a distributed barrier design; (ii) the Nb portions of the copper encased Nb rods in the final wire are of diameter from 0.5 to 7 m before reaction, and (iii) the Nb diffusion barrier that is fully or partially converted to Nb.sub.3Sn by heat treatment is from 0.8 to 11 m thickness before reaction; and e) heat treating the final size wire from step d) to form the Nb.sub.3Sn superconducting phases, and multifilament Nb.sub.3Sn superconducting wires made thereby are described herein.