Preparation method of superfine core wire multi-core MgB2 superconducting wire strip

Abstract

The invention discloses a preparation method of a superfine core wire multi-core MgB2 superconducting wire strip, which comprises the steps of 1, mixing tubing precursor powder, grinding to obtain mixed powder, and cleaning the surface of a wrapping material; 2, filling the mixed powder into a primary sheath, and drawing to obtain a single-core wire; 3, bundling and assembling a plurality of single-core wires, a central plunger and an edge plunger into a secondary sheath for vacuum seal welding; 4, sequentially carrying out hot extrusion, groove rolling and drawing, and matching an intermediate heat treatment process; and 5, performing phase forming heat treatment to obtain the superfine core wire multi-core MgB2 superconducting wire strip. According to the invention, through structural design and hot extrusion of the multiple single-core wires after bundling and assembling, the bonding strength between the sub-components is improved, the cooperative deformation capacity between the sub-components is guaranteed, the number of the superconducting core wires is increased, the diameter of the superconducting core wires is reduced, the alternating current loss performance of the multi-core MgB2 superconducting wire strip is reduced, and the requirement of alternating current transmission application is met.

Description

technical field [0001] The invention belongs to the technical field of superconducting wire strip processing, and in particular relates to an ultrafine core wire multi-core MgB 2 Method for producing superconducting wire tape. Background technique [0002] Magnesium diboride (MgB 2 ) is a metal compound with a simple binary structure that was successfully synthesized in the 1950s, but its superconductivity was not first discovered by Japanese scientists until 2001. MgB 2 The material has many advantages such as large coherence length, no weak connection phenomenon of grain boundary, simple crystal structure, and low cost of raw materials, and can be applied in the temperature range of 20K under liquid hydrogen. Current international MgB 2 Magnets, cables and other application research have made great progress, which is also the MgB 2 Materials, especially wires, put forward more and higher requirements. Such as requiring MgB 2 The wire has lower AC loss, higher transm...

AI Technical Summary

Problems solved by technology

To reduce MgB 2 The most direct process for the AC loss performance of the wire is to reduce the diameter of the superconducting core wire. Processing the wire to a smaller size can also obtain a superconducting wire with a smaller core wire diameter, but the process cost will be greatly increased, which is not conducive to For process promotion, another feasible solution is to increase the number of core wires. Of course, this puts forward higher requirements for the subsequent processing technology.

[0003] In view of the deficiencies in the above-mentioned prior art, this group once proposed an extrusion process to prepare multi-core MgB 2 The method of superconducting wire (ZL201410363120.8), but it is impossible to realize a thinner superconducting core wire, that is, a multi-core MgB with a diameter of less than 10 μm 2 Preparation of superconducting wire

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