Manufacturing method for practical multi-core MgB2 composite superconductive wire rods

Abstract

The invention discloses a manufacturing method for practical multi-core MgB2 composite superconductive wire rods. The method is performed through the following steps: 1) obtaining precursor powder by mixing and ball milling; 2) filling the powder into a Fe pipe; 3) obtaining single core wire rods through the process of drawing and intermediate annealing; 4) obtaining a multi-core wire rod by carrying out rotary swaging and drawing to the plurality of single core wire rods after they are coated with coalesced copper bands; and 5) obtaining a multi-core MgB2 superconductive wire rod through sintering in vacuum. The manufacturing method of the invention combines the advantages of a PIT method and a CTFF method wherein high quality single wire rods are manufactured through the PIT method and based on the single wire rods and through the CTFF method, a large sized multi-core MgB2 superconductive wire rod is manufactured effectively. According to the invention, the large sized multi-core MgB2 superconductive wire rod ensures both the quality of the single core wire rods and high manufacturing efficiency, meeting the practical need of superconductive materials and enabling the superconductive materials to be used in practice.

Description

technical field [0001] The invention belongs to the technical field of superconducting material processing engineering, in particular to a practical multi-core MgB 2 A method for preparing a composite superconducting wire. Background technique [0002] At the beginning of 2001, the Japanese scientist Professor Akimitsu Jun's research group first discovered MgB 2 The superconducting critical transition temperature T of the material C Up to 39K. Different from traditional low-temperature superconductors and oxide high-temperature superconductors, MgB 2 Superconducting materials have very simple chemical composition and crystal structure, grain boundaries can carry high current, and the cost of raw materials is low. At the same time MgB 2 The coherence length of the perovskite structure oxide superconductor is larger than that of the oxide superconductor, which means that MgB 2 It is easier to introduce effective flux pinning centers in . Based on its various characteris...

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Problems solved by technology

[0004] Patent "a multi-core MgB 2 Preparation method of superconducting wire / ribbon" (CN102280198A) and patent "a core reinforced MgB 2 In "Preparation method of superconducting wire / ribbon" (CN101989472A), the PIT method was used to prepare MgB with 7 cores, 13 cores, etc. 2 / Nb / Cu superconducting wire / tape, the length of the wire prepared by the above method is limited by the PIT method, and its length is difficult to break through, which limits the application of the wire in superconducting motor coils, etc.; the preparation process uses expensive Nb The use of tubes as a barrier layer and central reinforcement greatly increases the cost of wire preparation, weakens the advantage of low raw material prices of the superconducting material itself, and reduces the competitiveness of the actual large-scale application of the wire

In the patent "Preparation method of iron / copper composite sheathed magnesium diboride superconducting long wire" (CN1945759A), MgB with a length of tens of meters was prepared by the PIT method 2 / Fe / Cu superconducting wire, whose length is difficult to meet the requirements of practical applications

Patent "a solution coating method to prepare C-doped multi-core MgB 2 In "Preparation method of superconducting wire" (CN103956221A), a 7-core MgB 2 Superconducting short wires, in which Nb-Ti composite tubes plus oxygen-free copper tubes are used as sheathing materials in the preparation of single cores, the raw materials are expensive and the preparation process is complicated, which is not suitable for large-scale actual production. It is also difficult to meet the length requirements of industrial applications

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