Method for preparing superconducting joint of Bi-2212 wire rod

Abstract

The invention discloses a method for preparing a superconducting joint of a Bi-2212 wire rod. The method comprises the following steps: 1. cleaning a to-be-connected end of the Bi-2212 wire rod, and polishing the end; 2. corroding the polished surface of the wire rod subjected to polishing in a corrosive solution; 3. by taking a metal pipe of which one end is closed and the other end is open as a connecting piece, forming two through holes in the closed end of the metal pipe, and assembling two corroded wire rods and the metal pipe to obtained an assembly part; and 4. performing partial molten heat treatment on the assembly part to obtain the superconducting joint of the Bi-2212 wire rod. By adopting a chemical corrosion mode, a silver layer at the end of the Bi-2212 wire rod is effectively corroded, a superconducting core is exposed under the condition that a ceramic core is not damaged, a contact area between the ceramic core and the peripheral original powder is greatly enlarged, the performance of the superconducting joint is improved, and the current-carrying performance of the superconducting joint in the prepared superconducting joint of the Bi-2212 wire rod reaches 83-90 percent of the performance of the wire rod.

Description

technical field [0001] The invention belongs to the technical field of high-temperature superconducting joint preparation, and in particular relates to a preparation method of a Bi-2212 wire superconducting joint. Background technique [0002] Bi-based high-temperature superconductors (Bi 2 Sr 2 CaCu 2 o x and Bi 2 Sr 2 Ca 2 Cu 3 o x ) is the most important branch of high-temperature superconducting materials. Due to its easy processing and high current-carrying properties, it has become one of the most promising high-temperature superconducting materials. Among them, ultra-high field (> 1GHz) NMR is One of its most important fields of application. [0003] NMR systems often require closed-loop operation, and superconducting joints are one of the key links to achieve closed-loop operation. Only when the superconducting joint and the wire strip have similar current-carrying properties can the performance of the superconducting wire strip be fully utilized, and th...

AI Technical Summary

Problems solved by technology

Due to the secondary heat treatment in the preparation process of this joint, the overall performance of the wire and strip is reduced, which affects the effect of the superconducting joint.

In addition, the use of mechanical polishing to expose the superconducting core wire will cause damage to the wire strip itself

For Bi-2212 wire, this phenomenon is more prominent. The number of core wires of Bi-2212 wire exceeds 400 cores and the diameter of the core wire is only 20 μm to 30 μm. The mechanical polishing process will not only cause damage to the fragile superconducting core wire, Moreover, this mechanical method is almost impossible to really expose all the core wires, resulting in poor performance of the superconducting joint

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