Vacuum soldering technology for high temperature superconducting current shunt lead

Abstract

The invention discloses a vacuum soldering process for a high-temperature superconducting current lead shunt. The high-temperature superconducting current lead shunt includes a shunt body and a superconducting cable. A shunt copper head is provided between the shunt body and the superconducting cable. A joint box is provided at the other end of the superconducting cable. A superconducting stack is also provided on the outside of the shunt body. The shunt copper head is provided with a step tin groove, a superconducting cable groove is provided on the joint box, a superconducting stack groove is provided on the shunt body, one end of the superconducting cable is overlapped in the step tin groove after tinning, and the other end is overlapped in the superconducting cable groove after tinning. A superconducting stack groove is provided on the outside of the shunt body, and the superconducting stack is arranged in the superconducting stack groove. Tin material is provided in the step tin groove, the superconducting cable groove and the superconducting stack groove. Silicon rubber strips and stainless steel pressing plates are pressed on the outside in sequence, and the stainless steel pressing plates are positioned and fixed by bolts. The vacuum soldering process includes the steps of tinning and the like. The invention effectively improves the manufacturing efficiency and soldering quality of the high-temperature superconducting current lead shunt.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature superconductivity, and in particular to a vacuum soldering process for a high-temperature superconducting current lead shunt. Background Art

[0002] High-temperature superconducting current leads are one of the core components of the superconducting magnet feeder system of nuclear fusion devices. High-temperature superconducting current lead shunts are transition components in high-temperature superconducting current leads that transition from high-temperature superconductors to low-temperature superconductors, such as Figure 1 As shown, the high-temperature superconducting current lead shunt includes a shunt body 1 and a superconducting cable 2. A shunt copper head 3 is provided between the shunt body 1 and the superconducting cable 2. A junction box 4 is provided at the other end of the superconducting cable 2. The junction box 4 includes a box body 41 and a box cover 42. A superconducting stack 5 is also provided on the outside of the shunt body 1. When current is transmitted, it is transmitted from the superconducting stack 5 through the shunt copper head 3 and then to the superconducting cable 2.

[0003] The vacuum soldering process of the existing high-temperature superconducting current lead shunt is as follows: in order to ensure the stability of the entire structure during welding, the superconducting cable 2 needs to be split and then vacuum soldered with the shunt copper head 3 (the sub-cables are matched one by one with the copper head holes of the shunt copper head 3, and the sub-cables are inserted into the corresponding holes one by one for vacuum soldering), and then the other end of the superconducting cable 2 is vacuum soldered with the box body 31, and the box cover 42 needs to be welded to the box body 41, and finally the superconducting stack 5 is vacuum soldered on the shunt body 1. Not only are the process steps cumbersome and the manufacturing efficiency low, but also due to multiple vacuum soldering, it is difficult to ensure the soldering quality of the high-temperature superconducting current lead shunt. Summary of the invention

[0004] The object of the present invention is to provide a vacuum soldering process for a high-temperature superconducting current lead shunt, which can reduce the number of vacuum soldering times for the high-temperature superconducting current lead shunt and improve the soldering quality thereof.

[0005] A high-temperature superconducting current lead shunt comprises a shunt body and a superconducting cable, wherein a shunt copper head is arranged between the shunt body and the superconducting cable, a joint box is arranged at the other end of the superconducting cable, and a superconducting stack is arranged outside the shunt body; the shunt copper head is provided with a step tin groove, the joint box is provided with a superconducting cable groove, the shunt body is provided with a superconducting stack groove, one end of the superconducting cable is overlapped in the step tin groove after tinning, and the other end is overlapped in the superconducting cable groove after tinning, a superconducting stack groove is arranged outside the shunt body, and the superconducting stack is arranged in the superconducting stack groove, tin material is arranged in the step tin groove, the superconducting cable groove and the superconducting stack groove, and a silicone rubber strip and a stainless steel pressing plate are pressed in sequence on the outside, and the stainless steel pressing plate is positioned and fixed by bolts.

[0006] A vacuum soldering process for a high-temperature superconducting current lead shunt is provided, wherein the vacuum soldering is performed on the high-temperature superconducting current lead shunt. The vacuum soldering process comprises the following steps:

[0007] (1) Nickel removal at both ends of the superconducting cable:

[0008] (2) Tinning of both ends of the superconducting cable:

[0009] (3) Place tin in the superconducting cable groove of the joint box;

[0010] (4) Connect one end of the superconducting cable to the superconducting cable groove;

[0011] (5) Place tin in the step tin tank of the copper head of the diverter;

[0012] (6) Connect the other end of the superconducting cable to the stepped tin bath;

[0013] (7) Place tin material in the superconducting stack;

[0014] (8) Assembling the superconducting stack into the superconducting stack slot;

[0015] (9) Press a layer of silicone rubber and a layer of stainless steel pressing plate on one end of the superconducting cable in the step tin bath, the other end of the superconducting cable in the superconducting cable groove, and the superconducting stack in the superconducting stack groove. The stainless steel pressing plate is fixed in place by bolts. Repeat the steps until it is installed in place.

[0016] (10) Place the assembled high-temperature superconducting current lead shunt in a vacuum furnace and start evacuating the vacuum to 10 -2 Pa, heated to 200℃ and maintained at 200℃±5℃;

[0017] (11) Keep warm for 10 minutes. After that, turn off the heating device, cool to 60°C, and then pull out the high-temperature superconducting current lead shunt.

[0018] The present invention optimizes the structure and process of the high-temperature superconducting current lead shunt, and changes the original three-step vacuum soldering of the high-temperature superconducting current lead shunt to a one-step process, which not only effectively improves the manufacturing efficiency of the high-temperature superconducting current lead shunt, but also improves the soldering quality of the high-temperature superconducting current lead shunt. In addition, since the superconducting stack is directly soldered to the superconducting cable, the current does not need to pass through the shunt copper head during transmission, which reduces the contact resistance and improves the working performance of the high-temperature superconducting current lead shunt. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a structural schematic diagram of a high-temperature superconducting current lead shunt in the background technology;

[0021] Figure 2 It is a structural schematic diagram of the present invention;

[0022] Figure 3 It is a schematic diagram of the explosion structure of the present invention;

[0023] Figure 4 It is a structural schematic diagram of the diverter body in the present invention. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0025] See also Figure 2 The present embodiment provides a high-temperature superconducting current lead shunt, comprising a shunt body 1 and a superconducting cable 2, a shunt copper head 3 is arranged between the shunt body 1 and the superconducting cable 2, a joint box 4 is arranged at the other end of the superconducting cable 2, and a superconducting stack 5 is arranged on the outer side of the shunt body 1. In order to solve the technical problems described in the background technology, the high-temperature superconducting current lead shunt has a high structural stability before the three-step vacuum soldering, providing a basis for realizing the one-step vacuum soldering, combined with Figure 3 The technical solution of this embodiment is that the splitter copper head 3 is provided with a stepped tin bath 31, the joint box 4 is provided with a superconducting cable groove 41, and the Figure 4 A superconducting stack groove 11 is provided on the diverter body 1, one end of the superconducting cable 2 is lapped in the step tin groove 31 after tinning, and the other end is lapped in the superconducting cable groove 41 after tinning. A superconducting stack groove 11 is provided on the outside of the diverter body 1, and the superconducting stack 5 is arranged in the superconducting stack groove 11. Tin material is provided in the above-mentioned step tin groove 31, superconducting cable groove 41 and superconducting stack groove 11, and silicone rubber strips and stainless steel pressure plates are pressed on the outside in sequence, and the stainless steel pressure plate is positioned and fixed by bolts.

[0026] A vacuum soldering process for a high-temperature superconducting current lead shunt is provided, wherein the vacuum soldering is performed on the high-temperature superconducting current lead shunt. The vacuum soldering process comprises the following steps:

[0027] (1) Nickel removal at both ends of superconducting cable 2:

[0028] (1.1) The armor is removed from both ends of the superconducting cable by mechanical processing;

[0029] (1.2) After removing the armor, use the chemical nickel removal method. Place both ends vertically in an acid solution to remove nickel at 10-50°C, keep for 1-3 minutes, and take them out after the reaction stops;

[0030] (1.3) After nickel removal, the superconducting cable should be kept in a vertical state and rinsed with fresh deionized water at least 3 times. The water washing height must be greater than the acid washing height.

[0031] (2) Tinning of both ends of superconducting cable 2:

[0032] (2.1) Place the tin material (Sn63Pb37) into the tin melting furnace, turn on the tin melting furnace controller, and set the heating temperature to 240°C;

[0033] (2.2) Wait for the temperature of the tin melting furnace to stabilize to 200±5℃, immerse both ends of the superconducting cable 2 into the tin melting furnace, start timing, and take out the cable within 20 seconds;

[0034] (3) Put tin into the superconducting cable groove 41 of the joint box 4;

[0035] (3.1) Use alcohol to clean the surface of the superconducting cable groove 41 in the joint box 4 and the tin groove; ensure that the surface inside the groove is clean and free of pollution;

[0036] (3.2) Place the clean joint box 4 into the heating tool, connect the heating plate to the control system, and crimp the two temperature sensors of the control system onto the outer surface of the box;

[0037] (3.3) Turn on the control system power, start the heating and temperature measuring instrument, set the upper limit of the control temperature to 205℃ and the lower limit to 195℃. After heating to the set temperature, enter the insulation state to ensure that the surface temperature of the joint box 2 is 200±5℃;

[0038] (3.4) Place the tin sheet (Sn63Pb37) in the superconducting cable groove 41, and use a brush dipped in flux (NC585) to apply tin after it melts. Stop applying tin after the coating is evenly formed, and wipe off the flux and excess solder with a non-woven cloth;

[0039] (3.5) Turn off the heating control system, wait until the temperature of the box drops below 60°C, remove the heating control system and tooling, and remove the solder collected on it.

[0040] (4) Connect one end of the superconducting cable 2 to the superconducting cable groove 41 of the joint box 4;

[0041] (5) Put tin material into the step tin bath 31 of the diverter copper head 3;

[0042] (5.1) Fill the tin material (Sn63Pb37) into the step tin bath 31;

[0043] (6) Connect the other end of the superconducting cable 2 to the stepped tin bath 31 of the shunt copper head 3;

[0044] (7) Assembling the superconducting stack 5 in the superconducting stack groove 11;

[0045] (8) placing tin material (Sn63Pb37) into the superconducting stacking groove 11;

[0046] (9) Assembling the superconducting stacks 5 side by side into the superconducting stack slots 11;

[0047] (9.1) Press a layer of silicone rubber and a layer of stainless steel pressing plate on one end of the superconducting cable 2 in the step tin bath 31, the other end of the superconducting cable 2 in the superconducting cable groove 41, and the superconducting stack 5 in the superconducting stack groove 11, respectively. The stainless steel pressing plate is fixed in place by bolts. Repeat the steps until the installation is in place.

[0048] (10) Place the assembled high-temperature superconducting current lead shunt in a vacuum furnace and start evacuating the vacuum to 10 -2 Pa, heated to 200℃ and maintained at 200℃±5℃;

[0049] (11) Keep warm for 10 minutes. After that, turn off the heating device, cool to 60°C, and then pull out the high-temperature superconducting current lead shunt.

[0050] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A vacuum soldering process for a high-temperature superconducting current lead shunt, wherein the high-temperature superconducting current lead shunt is subjected to vacuum soldering. The high-temperature superconducting current lead shunt comprises a shunt body and a superconducting cable. A shunt copper head is arranged between the shunt body and the superconducting cable. A joint box is arranged at the other end of the superconducting cable. A superconducting stack is also arranged on the outside of the shunt body. Features: The copper head of the shunt is provided with a step tin groove, the joint box is provided with a superconducting cable groove, the shunt body is provided with a superconducting stacking groove, one end of the superconducting cable is tinned and overlapped in the step tin groove, and the other end is tinned and overlapped in the superconducting cable groove, the outer side of the shunt body is provided with a superconducting stacking groove, and the superconducting stack is arranged in the superconducting stacking groove, the step tin groove, the superconducting cable groove and the superconducting stacking groove are all provided with tin material, and the outer side is pressed with a silicone rubber strip and a stainless steel pressing plate in sequence, and the stainless steel pressing plate is positioned and fixed by bolts; The vacuum soldering process The following steps are involved: (1) Nickel removal at both ends of the superconducting cable: (2) Tinning of both ends of the superconducting cable: (3) Place tin in the superconducting cable groove of the joint box; (4) Connect one end of the superconducting cable to the superconducting cable groove; (5) Place tin in the step tin tank of the copper head of the diverter; (6) Connect the other end of the superconducting cable to the stepped tin bath; (7) Place tin material in the superconducting stack; (8) Assembling the superconducting stack into the superconducting stack slot; (9) Press a layer of silicone rubber and a layer of stainless steel pressing plate on one end of the superconducting cable in the step tin bath, the other end of the superconducting cable in the superconducting cable groove, and the superconducting stack in the superconducting stack groove. The stainless steel pressing plate is fixed in place by bolts. Repeat the steps until it is installed in place. (10) Place the assembled high-temperature superconducting current lead shunt in a vacuum furnace and start evacuating the vacuum to 10 -2 Pa, heated to 200℃ and maintained at 200℃±5℃; (11) Keep warm for 10 minutes. After that, turn off the heating device, cool to 60°C, and then pull out the high-temperature superconducting current lead shunt.

2. A vacuum soldering process for high temperature superconducting current lead shunt according to claim 1, characterized in that: The tin material is Sn63Pb37.

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