Superconducting joint hot pressing device and hot press

Abstract

The invention discloses a superconductive joint hot-pressing device, and relates to the technical field of high-temperature superconductive joint preparation, the superconductive joint hot-pressing device mainly comprises an upper pressing block, a lower pressing block and a heating piece, the upper pressing block is used for connecting the upper end of a hot press main body, the lower pressing block is used for connecting the lower end of the hot press main body, and the upper pressing block and the lower pressing block are vertically aligned and used for pressing a superconductive strip; the heating piece covers the outer sides of the upper pressing block and the lower pressing block in the circumferential direction of the upper pressing block and the lower pressing block. The invention further discloses a hot press which comprises a hot press body and the superconducting connector hot-pressing device, the upper end of the hot press body is provided with a pressure applying mechanism capable of applying pressure to the upper pressing block, and the lower end of the hot press body is provided with a fixing mechanism capable of fixing the lower pressing block. The device can heat uniformly, and the connecting effect of the superconducting tape is improved.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature superconducting joint preparation, in particular to a superconducting joint hot pressing device and a hot pressing machine. Background Art

[0002] Ultra-high performance superconducting tapes based on rare earth barium copper oxide (REBCO) are expected to be used in high-field magnetic resonance imaging magnets. However, since the length of a single tape is limited, it is very necessary to achieve a low-resistance connection between superconducting tapes. Since the superconducting joint hot pressing device can directly connect the superconducting layers and the joint is in a zero-resistance state, the superconducting joint hot pressing device is widely used. However, REBCO material is a ceramic material. During the connection process, a superconducting phase structure needs to be formed between the two REBCO layers, and the heating effect seriously affects whether a superconducting phase structure can be formed between the two superconducting tapes.

[0003] At present, there is a battery cell hot pressing device, which sets the battery cell in a confined space and uses the battery cell to heat the confined space. Since the battery cell is in a specific position in the confined space, the temperature distribution in the confined space is uneven, and the temperature close to the battery cell will be higher than the temperature far away from the battery cell, affecting the connection effect of the superconducting tape.

[0004] Therefore, there is an urgent need for a superconducting joint hot pressing device and a hot pressing machine to solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to provide a superconducting joint hot pressing device and a hot pressing machine to solve the problems existing in the above-mentioned prior art, and to achieve uniform heating and improve the connection effect of superconducting tapes.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a superconducting joint hot pressing device, comprising an upper pressing block, a lower pressing block and a heating element, wherein the upper pressing block is used to connect the upper end of a hot press body, and the lower pressing block is used to connect the lower end of the hot press body. The upper pressing block and the lower pressing block are aligned up and down and are used to press superconducting tapes, and the heating element covers the outer sides of the upper pressing block and the lower pressing block along the circumference of the upper pressing block and the lower pressing block.

[0008] In some embodiments, the heating element is a spiral heating wire, and the spiral heating wire is sleeved on the upper pressing block and the lower pressing block.

[0009] In some embodiments, the upper pressing block and the lower pressing block are both provided with a plurality of heat-through holes, and the heat-through holes can circulate heat.

[0010] In some embodiments, a pressure boss is provided on the upper pressure block, and the pressure boss is in the shape of a long strip and is provided at one end of the upper pressure block close to the lower pressure block. A pressure groove corresponding to the pressure boss is provided on the lower pressure block, and the pressure groove is in the shape of a long strip and is provided at one end of the lower pressure block close to the upper pressure block. The pressure boss can be inserted into the corresponding pressure groove.

[0011] In some embodiments, the opening direction of the heat-through hole is consistent with the length direction of the pressure boss and the pressure groove, and the heat-through hole on the upper pressure block is not located directly above the pressure boss, and the heat-through hole on the lower pressure block is not located directly below the pressure groove.

[0012] In some embodiments, an upper groove is provided on the top of the upper pressing block, and the upper groove is used to clamp the upper end of the hot press body. A lower groove is provided on the bottom of the lower pressing block, and the lower groove is used to clamp the lower end of the hot press body.

[0013] In some embodiments, the width of the pressure groove is 0.04-0.06 mm greater than the width of the pressure boss.

[0014] In some embodiments, the upper pressing block and the lower pressing block are both made of high temperature resistant material.

[0015] In some embodiments, a temperature measuring hole is further included, wherein the temperature measuring hole is disposed on the upper pressing block, and a thermocouple is disposed inside the temperature measuring hole.

[0016] The present invention also provides a hot press, comprising a hot press body and the superconducting joint hot pressing device as described above, wherein the upper end of the hot press body is a pressure mechanism capable of applying pressure to the upper pressing block, and the lower end of the hot press body is a fixing mechanism capable of fixing the lower pressing block.

[0017] Compared with the prior art, the present invention has achieved the following technical effects:

[0018] The upper pressing block of the superconducting joint hot pressing device provided by the present invention is used to connect the upper end of the hot press body, and the lower pressing block is used to connect the lower end of the hot press body. The upper pressing block and the lower pressing block are aligned up and down and are used to press the superconducting tape. The heating element covers the outer side of the upper pressing block and the lower pressing block along the circumference of the upper pressing block and the lower pressing block, so that the superconducting tape can be heated uniformly in the circumferential direction during the pressing process. All parts of the superconducting tape can reach the required hot pressing temperature at the same time, avoiding local overheating or overcooling, which is helpful to improve the hot pressing quality of the superconducting tape and enhance the performance of the superconducting tape. Moreover, the superconducting joint hot pressing device as a whole can be placed in the sealing box of the hot press body, and oxygen can be introduced, which can avoid the loss of oxygen elements in the superconducting tape, ensure the critical current of the superconducting joint, and then make a high-current joint. 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 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 A schematic diagram of the structure of a superconducting joint hot pressing device provided in some embodiments of the present invention;

[0021] Figure 2 A schematic diagram of a disassembly of a superconducting joint hot pressing device provided in some embodiments of the present invention;

[0022] Figure 3 A schematic diagram of the structure of an upper pressing block and a lower pressing block provided in some embodiments of the present invention;

[0023] Figure 4 The arrangement of two strips when preparing a silver diffusion joint provided in some embodiments of the present invention;

[0024] Figure 5 The diagram shows the arrangement of two strips when preparing a superconducting joint in some embodiments of the present invention.

[0025] In the figure: 1-upper end of the hot press body; 2-upper pressing block; 201-upper groove; 202-heat-passing hole; 203-pressure boss; 204-temperature measuring hole; 3-lower pressing block; 303-pressure groove; 4-lower end of the hot press body; 5-spiral heating wire; 6-silver layer; 7-superconducting layer. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The purpose of the present invention is to provide a superconducting joint hot pressing device and a hot pressing machine to solve the problems existing in the prior art, and to achieve uniform heating and improve the connection effect of superconducting tapes.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Embodiment 1

[0030] like Figure 1-Figure 5 As shown, the present invention provides a superconducting joint hot pressing device, including an upper pressing block 2, a lower pressing block 3 and a heating element, wherein the upper pressing block 2 is used to connect the upper end 1 of the hot press body, and the lower pressing block 3 is used to connect the lower end 4 of the hot press body. The upper pressing block 2 and the lower pressing block 3 are aligned up and down and are used to press the superconducting tape, and the heating element covers the outer side of the upper pressing block 2 and the lower pressing block 3 along the circumference of the upper pressing block 2 and the lower pressing block 3. Each part of the superconducting tape can reach the required hot pressing temperature at the same time, avoiding local overheating or overcooling, which is helpful to improve the hot pressing quality of the superconducting tape and enhance the performance of the superconducting tape. Moreover, the superconducting joint hot pressing device as a whole can be placed in the sealing box of the hot press body, and oxygen can be introduced, which can avoid the loss of oxygen elements in the superconducting tape, ensure the critical current of the superconducting joint, and then make a high-current joint.

[0031] In some embodiments, the heating element is a spiral heating wire 5, and the spiral heating wire 5 is sleeved on the upper pressing block 2 and the lower pressing block 3. The spiral-shaped heating wire is sleeved on the upper pressing block 2 and the lower pressing block 3, and can cover the surface of the pressing block over a large area. During the heating process, the heat can be distributed to various parts of the pressing block more evenly, and then more evenly transferred to the superconducting tape, reducing the uneven heating of the superconducting tape, ensuring the consistency of the temperature during the pressing process, and helping to improve the pressing quality and performance stability of the superconducting tape. The two ends of the spiral heating wire 5 are connected to the AC electrodes, and the resistance distribution of the spiral heating wire 5 is relatively uniform. By adjusting the current size, the heating temperature can be controlled more flexibly, so that the hot press can adapt to the hot pressing requirements of different types of superconducting tapes. For superconducting tapes of different materials and specifications, it can be accurately adjusted to a suitable hot pressing temperature, improving the versatility and adaptability of the equipment.

[0032] It should be noted that the heating element may also adopt heating devices of other structures, such as a plurality of circular rings spliced ​​from top to bottom, strip heating wires spliced ​​circumferentially, or a heating film.

[0033] In some embodiments, the upper pressing block 2 and the lower pressing block 3 are both provided with a plurality of heat-through holes 202, and the heat-through holes 202 can circulate heat. The presence of the heat-through holes 202 increases the channel for heat transfer, so that the heat generated by the heating element (such as the spiral heating wire 5) can be transferred to the inside of the pressing block more quickly through the heat-through holes 202, and then more quickly conducted to the superconducting tape, effectively shortening the heating time during the hot pressing process and improving the hot pressing efficiency. And the plurality of heat-through holes 202 are distributed on the upper pressing block 2 and the lower pressing block 3, and the heat can form a more uniform heat flow distribution inside the pressing block, which helps to avoid the situation where the local temperature of the pressing block is too high or too low, so that all parts of the superconducting tape can be evenly heated during the pressing process, thereby ensuring the pressing quality of the superconducting tape and improving the consistency and stability of its performance. The heat-through holes 202 may also have the advantage that during the hot pressing process, by controlling the power of the heating element, the temperature of the pressing block can be more accurately adjusted. Since heat can be transferred and dissipated through the heat through holes 202 in a timely manner, the temperature adjustment instruction can be responded to more quickly, and the hot pressing temperature can be accurately controlled to meet the strict requirements of different superconducting tapes on the hot pressing temperature.

[0034] It should be noted that when preparing silver diffusion joints, the heating temperature and pressure can generally be selected as 450°C and 20Mpa, and the hot pressing time is 20 minutes; when preparing superconducting joints, the heating temperature and pressure can generally be selected as 810°C and 20Mpa, and the hot pressing time is 20 minutes. There are mainly two types of joints that can be prepared: silver diffusion joints and superconducting joints. Among them, the silver diffusion joint is to align the top silver layers 6 of the superconducting layers 7 of the two strips face to face, that is, the silver layers 6 are in close contact. The silver layer 6 is melted and welded together by high temperature and high pressure, thereby preparing a silver diffusion welded joint, see Figure 4 The superconducting joint requires that the silver layer 6 on the surface of the strip be etched first to expose the superconducting layer 7, and then the superconducting layers 7 are welded face to face, see Figure 5 .

[0035] In some embodiments, a pressure boss 203 is provided on the upper pressing block 2, and the pressure boss 203 is arranged in a strip shape at the middle of one end of the upper pressing block 2 away from the upper end of the hot press body, and a pressure groove 303 corresponding to the pressure boss 203 is provided on the lower pressing block 3, and the pressure groove 303 is arranged in a strip shape at the middle of one end of the lower pressing block 3 away from the lower end of the hot press body. The pressure boss 203 is in a long strip shape, and the pressure groove 303 is also in a long strip shape. The pressure boss 203 and the pressure groove 303 are arranged correspondingly, and the pressure boss 203 can be inserted into the corresponding pressure groove 303. The corresponding arrangement of the pressure boss 203 and the pressure groove 303 provides accurate positioning guidance for the upper pressing block 2 and the lower pressing block 3 during the pressing process. When the hot press is working, the pressure boss 203 can accurately fall into the pressure groove 303, ensuring that the upper pressing block 2 and the lower pressing block 3 are accurately aligned when pressing the superconducting tape, avoiding offset or misalignment, thereby ensuring that the superconducting tape is evenly stressed during the pressing process and improving the pressing quality.

[0036] In some embodiments, the width of the pressure groove 303 is 0.04-0.06 mm greater than the width of the pressure boss 203, preferably 0.05 mm. The 0.05 mm width difference provides a certain margin for error. During the operation of the hot press, even if there is a slight position deviation between the upper pressing block 2 and the lower pressing block 3 when they are docked, the pressure boss 203 can easily fall into the pressure groove 303, reducing the risk of press failure caused by positioning deviation.

[0037] It should be noted that the width of the pressure boss 203 has various widths such as 4 mm, 6 mm, 8 mm, 12 mm, etc., which needs to be determined according to the width of the superconducting tape.

[0038] In some embodiments, the opening direction of the heat-through hole 202 is consistent with the length direction of the pressure boss 203 and the pressure groove 303, and the heat-through hole 202 on the upper pressing block 2 is not located directly above the pressure boss 203, and the heat-through hole 202 on the lower pressing block 3 is not located directly below the pressure groove 303. The heat-through hole 202 is along the length direction of the pressure boss 203 and the pressure groove 303 and avoids the two parts, so as to ensure the mechanical strength of the heat-through hole 202 and avoid damage, because if it is arranged perpendicular to the pressure boss 203 and the pressure groove 303 during the pressing process, the heat-through hole 202 may be squeezed and deformed directly above the pressure boss 203, and if it does not avoid the pressure boss 203 and the pressure groove 303, it may also be pressed and deformed. At the same time, the opening direction of the heat-through hole 202 is consistent with the length direction of the pressure boss 203 and the pressure groove 303, so that heat can be transferred directionally along the key parts of the pressing. During the hot pressing process, heat can be better concentrated in the area where the superconducting wire needs to be pressed, improving the heating efficiency and temperature uniformity in this area, helping the superconducting wire to better fuse and form during pressing, and improving the pressing quality.

[0039] As a preferred embodiment, four heat holes 202 are provided on the upper pressing block 2 and the lower pressing block 3, and two are provided on each side of the pressure boss 203. The two heat holes 202 on the same side are arranged up and down, which can provide good thermal conductivity.

[0040] In some embodiments, the top of the upper pressing block 2 is provided with an upper groove 201, and the upper groove 201 is used to clamp the upper end 1 of the hot press body, and the bottom of the lower pressing block 3 is provided with a lower groove, and the lower groove is used to clamp the lower end 4 of the hot press body. The upper groove 201 and the lower groove are set to provide accurate positioning for the connection between the upper pressing block 2, the lower pressing block 3 and the hot press body. During the installation process, the upper pressing block 2 and the lower pressing block 3 can accurately dock with the corresponding parts of the hot press body through the groove, ensuring that the position of the pressing block in the equipment is accurate and avoiding the problem of inaccurate pressing caused by installation deviation. The clamping method makes the connection between the upper pressing block 2, the lower pressing block 3 and the hot press body tighter. The cooperation between the groove and the hot press body can effectively transmit pressure and power. During the hot pressing process, even if it is subjected to greater pressure and vibration, the pressing block is not easy to loosen, fall off or shift, ensuring the stability of the hot press during long-term operation.

[0041] In some embodiments, the upper pressing block 2 and the lower pressing block 3 are both made of high temperature resistant materials, such as stainless steel, graphite, etc., which can ensure stable operation in a high temperature environment. High temperature resistant materials have good anti-aging properties, can effectively delay the material aging process caused by high temperature, extend the service life of the upper pressing block 2 and the lower pressing block 3, and reduce the maintenance and replacement costs of the equipment.

[0042] In some embodiments, the superconducting joint hot pressing device further comprises a temperature measuring hole 204, wherein the temperature measuring hole 204 is arranged on the upper pressing block 2, and a thermocouple is arranged inside the temperature measuring hole 204, and the thermocouple can measure the heating temperature and feed back the temperature to the computer control end. The thermocouple is directly arranged in the temperature measuring hole 204 of the upper pressing block 2, and can measure the heating temperature in the hot pressing process in real time and accurately, and feed back the measured temperature to the computer control end, and the computer control end can compare and analyze the actual measured temperature with the preset hot pressing temperature parameters, and then automatically adjust the heating power or other related parameters to ensure that the temperature in the hot pressing process is always stable near the set value.

[0043] Embodiment 2

[0044] The present invention also provides a hot press, including a hot press body and a superconducting joint hot pressing device as described in Example 1, which can heat evenly, improve the connection effect of superconducting tapes, and prepare silver diffusion welding joints, superconducting joints, etc. The upper end 1 of the hot press body is a pressure mechanism that can apply pressure to the upper pressing block 2, and the lower end 4 of the hot press body is a fixing mechanism that can fix the lower pressing block 3. The fixing mechanism at the lower end can firmly fix the lower pressing block 3, and cooperate with the pressure mechanism at the upper end to form a stable pressing structure. During the hot pressing process, no matter how much pressure the pressure mechanism applies, the lower pressing block 3 can remain fixed, ensuring that the relative position between the upper pressing block 2 and the lower pressing block 3 is accurate.

[0045] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A superconducting joint hot pressing device, characterized in that: It includes an upper pressing block, a lower pressing block and a heating element. The upper pressing block is used to connect the upper end of a hot press body, and the lower pressing block is used to connect the lower end of the hot press body. The upper pressing block and the lower pressing block are aligned up and down and are used to press the superconducting tape. The heating element covers the outer sides of the upper pressing block and the lower pressing block along the circumference of the upper pressing block and the lower pressing block.

2. The superconducting joint hot pressing device according to claim 1, characterized in that: The heating element is a spiral heating wire, and the spiral heating wire is sleeved on the upper pressing block and the lower pressing block.

3. The superconducting joint hot pressing device according to claim 1, characterized in that: The upper pressing block and the lower pressing block are both provided with a plurality of heat-through holes, and the heat-through holes can circulate heat.

4. The superconducting joint hot pressing device according to claim 3, characterized in that: The upper pressure block is provided with a pressure boss, which is in the shape of a long strip and is arranged at one end of the upper pressure block close to the lower pressure block. The lower pressure block is provided with a pressure groove corresponding to the pressure boss, which is in the shape of a long strip and is arranged at one end of the lower pressure block close to the upper pressure block. The pressure boss can be inserted into the corresponding pressure groove.

5. The superconducting joint hot pressing device according to claim 4, characterized in that: The width of the pressure groove is 0.04-0.06 mm greater than the width of the pressure boss.

6. The superconducting joint hot pressing device according to claim 4, characterized in that: The opening direction of the heat-through hole is consistent with the length direction of the pressure boss and the pressure groove, and the heat-through hole on the upper pressure block is not located directly above the pressure boss, and the heat-through hole on the lower pressure block is not located directly below the pressure groove.

7. The superconducting joint hot pressing device according to claim 1, characterized in that: An upper groove is arranged on the top of the upper pressing block, and the upper groove is used to clamp the upper end of the hot press body. A lower groove is arranged on the bottom of the lower pressing block, and the lower groove is used to clamp the lower end of the hot press body.

8. The superconducting joint hot pressing device according to claim 1, characterized in that: The upper pressing block and the lower pressing block are both made of high temperature resistant material.

9. The superconducting joint hot pressing device according to claim 1, characterized in that: It also includes a temperature measuring hole, which is arranged on the upper pressing block and has a thermocouple arranged inside the temperature measuring hole.

10. A hot press, characterized in that: It comprises a hot press body and a superconducting joint hot pressing device as described in any one of claims 1 to 9, wherein the upper end of the hot press body is a pressure mechanism capable of applying pressure to the upper pressing block, and the lower end of the hot press body is a fixing mechanism capable of fixing the lower pressing block.

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