Preparation method of multi-core MgB2 superconducting wire

Abstract

The invention discloses a preparation method of a multi-core MgB2 superconducting wire. The method comprises: first, precursor power is prepared; second, the precursor power is placed in a Ta tube to prepare a tubulation complex; third, groove rolling is carried out on a single core wire; fourth, a NbTi / Cu composite rod and a plurality of single core wires are placed in an oxygen-free copper tubefor assembling so as to obtain a secondary composite rod; fifth, rotary swaging and drawing are carried out on the secondary composite rod, groove rolling is carried out and rotary swaging and drawing are carried out again, so that a multi-core wire is obtained; and sixth, heat treatment is carried out on the multi-core wire to obtain a multi-core MgB2 superconducting wire. According to the invention, processes of rotary swaging, drawing and groove rolling are combined and employed; therefore, not only is density of the multi-core wire improved, but also connectivity between crystal grains can be improved; it is beneficial to prepare a multi-core MgB2 superconducting wire with high performances; and the prepared wire has high mechanical strength and can bear great stress and strain without obvious reduction of the superconductive current carrying performance, so that a superconducting wire practical requirement can be well met.

Description

technical field [0001] The invention belongs to the technical field of superconducting material processing engineering, and in particular relates to a multi-core MgB 2 Preparation method of superconducting wire. Background technique [0002] MgB 2 Since the superconductor was discovered in 2001, due to its critical temperature of 39K, its advantages such as large coherence length and no weak grain boundary connection, it has attracted the attention of scientists at home and abroad. After ten years of extensive and systematic research, It was found that elemental doping is to enhance the MgB 2 It is an effective means of high-field current-carrying capacity of the wire, and TiC doping is currently recognized as one of the most effective dopants. MgB 2 Wire preparation, especially wire preparation that meets practical requirements, has always been the focus of research. At present, many international manufacturers (such as Hype Tech in the United States, Columbus in Italy,...

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Problems solved by technology

However, because many sheath materials include commonly used Nb, Fe, etc., when the heat treatment temperature is high (greater than 750 degrees), the sheath material will chemically react with Mg or B to form a certain thickness of the diffusion layer. It will inhibit the critical current density of the wire, and due to the low heat treatment temperature, the carbon atoms in the TiC dopant are difficult to replace the boron atoms, and the TiC dopant can only exist at the grain boundary as a two-phase particle, which is very difficult It is difficult to significantly increase the critical current density of the wire under high field

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