Superconducting wire core material, multi-core compound superconducting wire made of superconducting wire core material, and preparation method of multi-core compound superconducting wire

Abstract

The invention discloses a superconducting wire core material, which is prepared from magnesium powder, amorphous boron powder and nanocarbon crystal, wherein the molar ratio of the magnesium powder to the boron powder is 1: (1.9-2), and the ratio of the total mass of the magnesium powder and the boron powder to the mass of the nanocarbon crystal is 1:(0.01-0.1). A multi-core compound superconducting wire made of the superconducting wire core material is characterized in that a compound canning tube is arranged out of the superconducting wire core material, the compound canning tube is successively provided with a first stainless steel tube barrier layer, a second stainless steel tube barrier layer and a first copper tube canning layer from inside to outside; the core material and the compound canning tube form single-core superconducting wires; the single-core superconducting wires are evenly and tightly arranged from outside to inside along the inner wall of a second copper tube canning layer to obtain a multi-core compound canning tube; a copper bar is inserted into the gap of the cross section of the multi-core compound canning tube; and the multi-core compound canning tube and the copper bar form the multi-core compound superconducting wire. Meanwhile, the invention also further discloses a preparation method of the multi-core compound superconducting wire. The multi-core compound superconducting wire and the superconducting wire core material have the advantages of good compactness and high critical current density.

Description

technical field [0001] The invention belongs to the technical field of superconducting materials, in particular to a superconducting MgB 2 Composite sheathed wire core material and superconducting MgB made of the core material 2 Composite sheathed wire and its preparation method. Background technique [0002] Compared with traditional low-temperature superconducting materials, the superconducting transition temperature of magnesium diboride is 39K, which is between low-temperature superconducting materials and high-temperature superconducting materials. Compared with high-temperature superconducting materials with perovskite structure, the anisotropy of magnesium diboride is relatively small, and the crystal structure of magnesium diboride is simple, which is hexagonal, and The preparation is relatively easy and the manufacturing cost is low; moreover, magnesium diboride has a coherence length greater than the atomic radius, and the superconducting current is not limited b...

AI Technical Summary

Problems solved by technology

However, there are still the following disadvantages: in the process of high temperature reaction, the molten Mg diffuses to B, and because the surface activity of B is very low, B is difficult to diffuse to Mg, which will leave pores in the original position of Mg, resulting in diboration There are many voids in magnesium, and the density is poor. Usually, its density is about 55% of the theoretical density. The lower density will have an adverse effect on the superconducting properties of magnesium diboride.

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