A method of adding nano-copper to prepare bi‑2223/ag multi-core superconducting tape

Abstract

The invention discloses a method for preparing a Bi-2223-Ag multi-core superconductive strip material by adding nano-copper. The method comprises the steps that 1, copper-short Bi-2223 precursor powder is prepared, sintered and subjected to ball milling by adding nano-copper powder, the materials are mixed to be uniform, and then tubing precursor powder is obtained; 2, a tubing compound is prepared in a tubing mode; 3, the tubing compound is processed into a single-core wire material in a drawing mode; 4, the single-core wire material is sequentially sized, cut, strengthened and washed, and then a multi-core wire material is prepared by adopting a bundle drawing method; 5, the multi-core wire material is rolled into the multi-core strip material, and heat treatment is conducted to obtain the Bi-2223-Ag multi-core superconductive strip material. According to the method, part of copper in the Bi-2223 precursor powder is replaced with an appropriate amount of the nano-copper powder, oxygen adsorbed by the powder is absorbed by the nano-copper powder to generate copper oxide in final heat treatment, and therefore influences of an impurity phase on the strip material properties are avoided; in addition, the bubbling phenomenon can be prevented as far as possible on the premise that the current carrying property of the strip material can be guaranteed, and the uniformity of the strip material properties is improved.

Description

technical field [0001] The invention belongs to the technical field of preparation of superconducting wire strips, in particular to a method for preparing Bi-2223 / Ag multi-core superconducting strips by adding nanometer copper. Background technique [0002] Bi-2223 (Bi 2 Sr 2 Ca 2 Cu 3 o x ) High-temperature superconductor is the most important branch of high-temperature superconducting materials. Because of its easy processing and high current-carrying performance, it has become one of the most promising high-temperature superconducting materials. At present, the preparation technology combining the powder-in-tube method (PIT) and the melting method is the mainstream technology for preparing high-performance Bi-based high-temperature superconducting wire strips. This technology is to put the superconducting precursor powder into the silver tube, prepare a multi-core composite by drawing and assembling, and then process it to the designed wire strip size, and then perfo...

AI Technical Summary

Problems solved by technology

Even if choosing a reasonable heat treatment system can greatly reduce the C content in the powder, but in the later tube loading process, if the control is not proper due to the high activity of the powder, it is easy to absorb H in the air. 2 O and CO 2 gas, causing eventual bubbling to occur

The use of high-pressure heat treatment can largely suppress the occurrence of bubbling, and at the same time increase the density of the core wire, so that high current-carrying performance can be obtained, but suitable high-voltage equipment is very expensive. Currently, only Sumitomo Corporation of Japan has such equipment, and it is in the For reasons of technical secrecy, the export of equipment is prohibited

However, due to various reasons in China, the high-pressure heat treatment equipment manufactured in China has not significantly improved the current-carrying performance of the strip. Therefore, it is very necessary to avoid the occurrence of bubbling and improve the uniformity of the strip performance through reasonable technological improvements.

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