Superconducting stack brazing method and mold for high-temperature superconducting current leads

A current lead, high temperature superconducting technology, applied in the direction of superconducting magnets/coils, circuits, electrical components, etc., can solve the problems of fragility of HTS belts, loss of superconductivity, loss of superconducting belts, etc.

CN101409129BInactive Publication Date: 2011-12-28INST OF PLASMA PHYSICS CHINESE ACAD OF SCI
0 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2011-12-28
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention discloses a superconducting stack brazing method and a mold for high-temperature superconducting current leads. The superconducting strips to be welded and the brazing welding strips are alternately put into a mold cavity made of a metal material with good thermal conductivity. The mold core and counterweight are pressed on the superconducting tape. Under vacuum conditions, the mold is heated to the brazing temperature and kept for 10-15 minutes, and then the mold is rapidly cooled to the solidification point of the brazing material to complete the welding. The critical current of the high-temperature superconducting tape with low thermal conductivity is only 100-120A under the self-field of 77K, which is much smaller than the operating current of thousands to tens of thousands of amperes of large superconducting magnets. The superconducting tapes must be welded and stacked for use. The price of the bismuth-based superconducting tape using Ag-5.3wt.% Au alloy as the matrix is ​​5-6 times that of the ordinary bismuth-based superconducting tape; and the price of the superconducting stack of foreign high-temperature superconducting companies is almost doubled. The method of the invention welds the superconducting stack with the mold, which can ensure that the current-carrying performance will not be degraded, the longitudinal heat leakage will not be increased, the welding between the superconducting strips is even, and the performance requirement of low interlayer resistance can be met.
Need to check novelty before this filing date? Find Prior Art

Description

Technical field:

[0001] The invention relates to a high temperature superconducting current lead stack brazing method and a mold for a large superconducting magnet. Background technique:

[0002] In the 21st century, China will apply superconducting technology to high-energy accelerators, nuclear fusion experimental devices, high-field magnets and energy storage magnets on a large scale. The difficulty and high operating costs of 4K low-temperature refrigeration technology have hindered the application of low-temperature superconductivity, in which the current leads feeding large superconducting magnets are the most important heat load. The use of high temperature superconducting (HTS) current leads can reduce the 4.5K thermal load by an order of magnitude. High-temperature superconducting current leads for small superconducting magnets are commercially available, but high-current leads need to be made by themselves with low thermal conductivity Bi-2223 tape.

[0003] For ...

Examples

Embodiment Construction

[0032] The mold used in the present invention includes a bottom plate 1 on which a middle formwork 2 is connected. The side wall of the middle template 2 has a mold groove 3 with an open side. A mold core 4 is inserted above the mold groove 3, and the thickness and width of the mold core just match the slot and are movable. A side plate 5 is covered on the outside of the mold cavity 3, and this side plate 5 is fixed on the middle template 2. The bottom plate 1, the middle formwork 3, and the bottom plate 2 are all made of hard aluminum alloy.

[0033] A copper plate is inserted between the bottom plate of the brazing mold and the flat electric furnace, and cooling water pipes are arranged on the side of the copper plate.

[0034] Prepare solder strips before soldering. Too thick solder strips will waste solder, and make excess solder squeeze out from the side, increasing the width of the stack. Therefore, the thickness of the selected solder strips should be as thin as possi...