A rare earth barium copper oxide block and its preparation method

Abstract

The present invention provides a rare earth barium copper oxide bulk material and a preparation method thereof, belonging to the technical field of superconducting material preparation. The method first removes the metal protective layer from the REBCO strip, exposing the silver layer in the REBCO strip. The silver layer is then overlapped with the silver ribbon and hot-pressed, allowing the silver layer and the silver ribbon to diffusely bond together, improving their mechanical properties. The metal alloy base strip and buffer layer in the silver ribbon / REBCO strip are then peeled off. During this process, the silver layer and silver ribbon provide support, thereby preventing damage to the REBCO superconducting layer and completely separating the REBCO superconducting layer from the buffer layer. Finally, the silver ribbon and silver layer in the silver ribbon / silver layer / REBCO superconducting layer are removed by etching, resulting in a complete REBCO superconducting layer.

Description

Technical Field

[0001] The present invention relates to the technical field of superconducting material preparation, in particular to a rare earth barium copper oxide block material and a preparation method thereof. Background Art

[0002] Rare earth barium copper oxide (REBa2Cu3O 7-x , abbreviated as REBCO, where RE stands for rare earth elements such as Y and Gd) materials have the advantages of high critical transition temperature, critical current density and irreversible field. High-temperature superconducting blocks and stacked strips made of REBCO materials can be excited by an external magnetic field to become trapped field magnets, generating a magnetic field much larger than that of conventional permanent magnets. They have broad application prospects in the fields of electricity, energy, strong magnetic fields and magnetic levitation transportation.

[0003] The magnitude of the trapping field is positively correlated with the critical current density of the REBCO material. Compared to the REBCO superconducting layer in a superconducting tape, the critical current density of conventional REBCO superconducting bulk materials is two orders of magnitude lower, resulting in a larger volume and hindering the generation of a higher trapping field. REBCO tape is typically composed of a metal alloy base tape (50-100 μm), a buffer layer (~200 nm), a REBCO superconducting layer (1-2 μm), a silver layer (~2 μm), and a metal protective layer (40-80 μm). The superconducting layer in REBCO tape has an extremely high critical current density, so stacking superconducting tapes into bulk materials can also achieve a higher trapping field. However, because the base tape, silver layer, and protective layer account for a high proportion of the tape thickness (up to 99%), the resulting bulk material is also larger, resulting in a low engineering current density (the ratio of the critical current of the superconducting layer to the total cross-sectional area of ​​the tape), which is also not conducive to generating a higher trapping field.

[0004] Because the interlayer bonding between the superconducting layer and the buffer layer in a REBCO tape is weakest, the REBCO superconducting layer can be separated from the tape and stacked to form a bulk material, thereby achieving a higher trapping field. Importantly, the separated REBCO superconducting layer lacks the thickness of a conventional superconducting bulk tape and the outer silver and protective layers of the superconducting tape. Particle irradiation can effectively penetrate the tape, creating suitable pinning centers, thereby effectively increasing the critical current density of the superconducting layer under a magnetic field. However, due to the thinness of the REBCO superconducting layer in the superconducting tape, it is prone to breakage and other problems during the separation process, resulting in a high scrap rate during separation and significantly increasing costs.

[0005] Therefore, how to completely and efficiently separate the REBCO superconducting layer from the tape so as to prepare rare earth barium copper oxide bulk materials with excellent conductive properties and high critical current density has become a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0006] The object of the present invention is to provide a rare earth barium copper oxide bulk material and a preparation method thereof. The rare earth barium copper oxide bulk material prepared by the REBCO superconducting layer provided by the present invention has excellent electrical conductivity and can significantly improve its critical current density and engineering current density under a magnetic field.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a method for separating a REBCO superconducting layer from a REBCO tape, comprising the following steps:

[0009] (1) removing the metal protective layer from the REBCO strip to obtain a REBCO strip without the metal protective layer;

[0010] (2) hot pressing a composite silver ribbon on the silver layer surface of the REBCO ribbon without a metal protective layer obtained in step (1) to obtain a silver ribbon / REBCO ribbon;

[0011] (3) peeling off the metal alloy base strip and the buffer layer in the silver strip / REBCO strip obtained in step (2) to obtain a silver strip / silver layer / REBCO superconducting layer;

[0012] (4) etching the silver ribbon and silver layer in the silver ribbon / silver layer / REBCO superconducting layer obtained in step (3) to obtain a REBCO superconducting layer.

[0013] Preferably, the hot pressing in step (2) is carried out in a roller.

[0014] Preferably, the hot pressing temperature in step (2) is 400-960° C., the hot pressing pressure is 1-50 MPa, and the running speed of the REBCO strip without metal protective layer and the silver strip during hot pressing is 0.001-1 m / min.

[0015] Preferably, the etching solution used in step (4) is a silver etchant.

[0016] The present invention provides a REBCO superconducting layer prepared by the method described in the above technical solution.

[0017] The present invention provides a rare earth barium copper oxide bulk material, which is prepared by the REBCO superconducting layer prepared by the method described in the above technical solution or the REBCO superconducting layer described in the above technical solution.

[0018] The present invention provides a method for preparing the rare earth barium copper oxide bulk material, comprising the following steps:

[0019] 1) subjecting the REBCO superconducting layer to oxidation annealing heat treatment and particle irradiation in sequence to obtain a high-performance REBCO superconducting layer;

[0020] 2) Cutting and stacking the high-performance REBCO superconducting layers obtained in step 1) in sequence to obtain rare earth barium copper oxide bulk materials.

[0021] Preferably, the temperature of the oxidation annealing heat treatment in step 1) is 350-600° C., the time of the oxidation annealing heat treatment is 0.5-2 h, and the atmosphere of the oxidation annealing heat treatment is an oxygen atmosphere.

[0022] Preferably, the particle irradiation in step 1) is carried out by using 60-300 keV protons at 10 14 ~10 17 p / cm 2 doses of irradiation.

[0023] Preferably, after obtaining the rare earth barium copper oxide bulk material in step 2), the process further comprises curing the rare earth barium copper oxide bulk material with a low temperature resistant epoxy resin.

[0024] The present invention provides a method for separating a REBCO superconducting layer from a REBCO tape, comprising the following steps: (1) removing a metal protective layer from the REBCO tape to obtain a REBCO tape without the metal protective layer; (2) hot-pressing a composite silver tape on the surface of the silver layer of the REBCO tape without the metal protective layer obtained in step (1) to obtain a silver tape / REBCO tape; (3) stripping the metal alloy base tape and the buffer layer from the silver tape / REBCO tape obtained in step (2) to obtain a silver tape / silver layer / REBCO superconducting layer; and (4) etching the silver tape and the silver layer in the silver tape / silver layer / REBCO superconducting layer obtained in step (3) to obtain a REBCO superconducting layer. The present invention first removes the metal protective layer in the REBCO strip to expose the silver layer in the REBCO strip. Then, the silver layer and the silver strip are overlapped and hot-pressed to allow the silver layer and the silver strip to be diffusely connected together, thereby improving their mechanical properties. Then, the metal alloy base strip and the buffer layer in the silver strip / REBCO strip are peeled off. During this process, the silver layer and the silver strip can play a supporting role, thereby avoiding damage to the REBCO superconducting layer and completely separating the REBCO superconducting layer from the buffer layer. Finally, the silver strip and the silver layer in the silver strip / silver layer / REBCO superconducting layer are removed by etching to obtain a complete REBCO superconducting layer.

[0025] The method for preparing a rare earth barium copper oxide bulk material provided by the present invention separates the REBCO superconducting layer from the tape and stacks them to form a bulk material. This significantly reduces the bulk material's volume, increases the engineering current density, facilitates magnetic flux penetration, and thus achieves a higher trapping field. Furthermore, compared to superconducting bulk materials and bulk materials formed from stacked tapes, the individual REBCO superconducting layers are very thin and unobstructed by other materials on the surface. Therefore, they are more suitable for introducing pinning centers within the film using particle irradiation, thereby improving its critical current density under magnetic fields. Furthermore, compared to directly stacking superconducting tapes to form a bulk material, stacking only REBCO superconducting layers to form a bulk material effectively reduces eddy current losses caused by the metal layer in the tape.

[0026] The results of the examples show that the rare earth barium copper oxide bulk material prepared with the REBCO superconducting layer provided by the present invention can retain more than 90% of the critical current of the REBCO tape and has excellent electrical conductivity. The Jc of the irradiated REBCO superconducting layer is nearly 100% higher than that of the REBCO tape, indicating that the rare earth barium copper oxide bulk material prepared with the REBCO superconducting layer provided by the present invention can significantly improve its critical current density under a magnetic field. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flow chart of the present invention for preparing rare earth barium copper oxide bulk material using REBCO strip;

[0028] Figure 1 In the figure, 1 is a silver ribbon, 2 is a REBCO ribbon, 21 is a silver layer, 22 is a REBCO superconducting layer, 23 is a buffer layer, 24 is a metal alloy substrate, 3 is a roller, 4 is a silver ribbon / silver layer / REBCO superconducting layer, 5 is a silver etchant, 6 is a REBCO superconducting layer, 7 is an oxidation annealing heat treatment, 8 is a particle irradiation, 9 is a stacked rare earth barium copper oxide block, and 10 is a low-temperature resistant epoxy resin;

[0029] Figure 2 VI curves of the REBCO superconducting layer prepared in Example 1 of the present invention and the original unirradiated REBCO tape provided in Comparative Application Example 1;

[0030] Figure 3 Jc-B curves of the high-performance REBCO superconducting layer prepared in Application Example 1 of the present invention and the REBCO tape provided in Comparative Application Example 1. DETAILED DESCRIPTION

[0031] The present invention provides a method for separating a REBCO superconducting layer from a REBCO tape, comprising the following steps:

[0032] (1) removing the metal protective layer from the REBCO strip to obtain a REBCO strip without the metal protective layer;

[0033] (2) hot pressing a composite silver ribbon on the silver layer surface of the REBCO ribbon without a metal protective layer obtained in step (1) to obtain a silver ribbon / REBCO ribbon;

[0034] (3) peeling off the metal alloy base strip and the buffer layer in the silver strip / REBCO strip obtained in step (2) to obtain a silver strip / silver layer / REBCO superconducting layer;

[0035] (4) etching the silver ribbon and silver layer in the silver ribbon / silver layer / REBCO superconducting layer obtained in step (3) to obtain a REBCO superconducting layer.

[0036] The invention removes the metal protective layer in the REBCO strip to obtain the REBCO strip without the metal protective layer.

[0037] The present invention has no particular limitation on the specific source of the REBCO strip, and commercially available products well known to those skilled in the art may be used.

[0038] The present invention has no particular limitation on the method of removing the metal protective layer, as long as the metal protective layer can be removed without damaging the silver layer inside.

[0039] After obtaining the REBCO strip without the metal protective layer, the present invention hot presses a composite silver strip on the silver layer surface of the REBCO strip without the metal protective layer to obtain a silver strip / REBCO strip.

[0040] The present invention has no particular limitation on the specific source of the silver ribbon. Commercially available products known to those skilled in the art can be used, or the silver ribbon can be prepared by the technicians themselves and its size can meet the requirements.

[0041] In the present invention, the length and width of the silver ribbon are preferably the same as those of the REBCO ribbon without the metal protective layer. The thickness of the silver ribbon is preferably 20 to 100 μm, more preferably 30 to 80 μm, and even more preferably 50 to 70 μm. By controlling the size of the silver ribbon, the present invention ensures that the silver ribbon and REBCO ribbon have good mechanical properties after hot pressing, facilitating the subsequent peeling and removal of the metal alloy base ribbon and buffer layer.

[0042] In the present invention, the hot pressing is preferably performed using rollers; the number of rollers is preferably two; and the distance between the center axes of the two rollers is preferably ≥ 10 cm. In the present invention, the temperature of the rollers is preferably 400-960°C, more preferably 500-800°C, and even more preferably 600-700°C. By controlling the temperature and spacing of the rollers, the hot pressing temperature and pressure can be regulated, thereby further promoting diffusion bonding between the silver layer and the silver ribbon.

[0043] In the present invention, the hot pressing temperature is preferably 400-960°C, more preferably 500-800°C, and even more preferably 600-700°C; the hot pressing pressure is preferably 1-50 MPa, more preferably 5-40 MPa, and even more preferably 10-30 MPa; the running speed of the REBCO strip without a metal protective layer and the silver strip during the hot pressing is preferably 0.001-1 m / min, more preferably 0.01-0.8 m / min, and even more preferably 0.1-0.5 m / min; and the hot pressing atmosphere is preferably an oxygen atmosphere. By controlling the hot pressing temperature and time, the present invention can avoid excessively high temperatures that cause silver to melt, resulting in discontinuity or breakage of the silver strip after hot pressing, ultimately leading to incomplete stripping of the REBCO superconducting layer or breakage at certain points; and can also avoid excessively low temperatures that cause incomplete diffusion connection between the silver strip and the silver layer, resulting in numerous pores and preventing complete stripping of the superconducting layer.

[0044] After obtaining the silver ribbon / REBCO ribbon, the present invention peels off the metal alloy base ribbon and the buffer layer in the silver ribbon / REBCO ribbon to obtain the silver ribbon / silver layer / REBCO superconducting layer.

[0045] In the present invention, the peeling method preferably involves keeping the silver / REBCO ribbon straight and then bending the metal alloy base ribbon and buffer layer from one end to peel them apart. The bending radius during the peeling is preferably greater than 5 mm. By controlling the bending radius, the present invention ensures that the metal alloy base ribbon and buffer layer are separated from the silver layer and REBCO superconducting layer without damaging the REBCO superconducting layer.

[0046] After obtaining the silver ribbon / silver layer / REBCO superconducting layer, the present invention etches the silver ribbon and silver layer in the silver ribbon / silver layer / REBCO superconducting layer to obtain the REBCO superconducting layer.

[0047] In the present invention, the etching solution used for the etching is preferably a silver etchant. The present invention has no particular limitation on the specific source of the silver etchant, and commercially available products well known to those skilled in the art can be used.

[0048] The present invention has no particular limitation on the etching time, as long as the silver ribbon and silver layer in the silver ribbon / silver layer / REBCO superconducting layer are completely removed. By removing the silver ribbon and silver layer by etching, the present invention can avoid damaging the REBCO superconducting layer, thereby obtaining a complete REBCO superconducting layer.

[0049] The present invention first removes the metal protective layer in the REBCO strip to expose the silver layer in the REBCO strip. Then, the silver layer and the silver strip are overlapped and hot-pressed to allow the silver layer and the silver strip to be diffusely connected together, thereby improving their mechanical properties. Then, the metal alloy base strip and the buffer layer in the silver strip / REBCO strip are peeled off. During this process, the silver layer and the silver strip can play a supporting role, thereby avoiding damage to the REBCO superconducting layer and completely separating the REBCO superconducting layer from the buffer layer. Finally, the silver strip and the silver layer in the silver strip / silver layer / REBCO superconducting layer are removed by etching to obtain a complete REBCO superconducting layer.

[0050] The present invention provides a REBCO superconducting layer prepared by the method described in the above technical solution. The REBCO superconducting layer obtained by the present invention has good integrity and is not damaged or broken.

[0051] The present invention also provides a rare earth barium copper oxide bulk material, which is prepared by the REBCO superconducting layer prepared by the method described in the above technical solution or the REBCO superconducting layer described in the above technical solution.

[0052] The present invention also provides a method for preparing the rare earth barium copper oxide bulk material, comprising the following steps:

[0053] 1) subjecting the REBCO superconducting layer to oxidation annealing heat treatment and particle irradiation in sequence to obtain a high-performance REBCO superconducting layer;

[0054] 2) Cutting and stacking the high-performance REBCO superconducting layers obtained in step 1) in sequence to obtain rare earth barium copper oxide bulk materials.

[0055] The invention sequentially performs oxidation annealing heat treatment and particle irradiation on a REBCO superconducting layer to obtain a high-performance REBCO superconducting layer.

[0056] In the present invention, the temperature of the oxidation annealing heat treatment is preferably 350-600°C, more preferably 400-550°C, and even more preferably 450-500°C; the duration of the oxidation annealing heat treatment is preferably 0.5-2 hours, more preferably 1-1.5 hours; and the atmosphere of the oxidation annealing heat treatment is preferably an oxygen atmosphere. By subjecting the REBCO superconducting layer to oxidation annealing heat treatment, the present invention can restore the superconducting properties lost during the stripping process, thereby obtaining a REBCO superconducting layer with excellent superconducting properties. By controlling the parameters of the oxidation annealing heat treatment, the superconducting properties can be further improved.

[0057] In the present invention, the particle irradiation method is preferably: using 60-300 keV protons at 10 14 ~10 17 p / cm 2The irradiation is carried out at a dose of 10, more preferably: using 60 to 200 keV protons at a dose of 10 14 ~10 16 p / cm 2 The irradiation is carried out at a dose of 10, more preferably: using 60-100 keV protons at a dose of 10 15 ~10 16 p / cm 2 The present invention introduces pinning centers into the REBCO superconducting layer by irradiating the REBCO superconducting layer with particles, thereby increasing the critical current density under a magnetic field.

[0058] After obtaining the high-performance REBCO superconducting layer, the present invention cuts and stacks the high-performance REBCO superconducting layer in sequence to obtain a rare earth barium copper oxide bulk material.

[0059] The present invention has no particular limitation on the specific operations of cutting and stacking. According to the required size of the rare earth barium copper oxide block, operations well known to those skilled in the art can be adopted.

[0060] The present invention has no special requirements on the size of the rare earth barium copper oxide block material, and it can be prepared according to actual needs.

[0061] After obtaining the rare earth barium copper oxide block material, the present invention preferably further comprises curing the rare earth barium copper oxide block material with a low temperature resistant epoxy resin. The present invention has no special limitation on the specific model and source of the low temperature resistant epoxy resin, and commercially available products familiar to those skilled in the art can be used. The present invention has no special requirements on the amount and thickness of the low temperature resistant epoxy resin used in the curing process and the process used in the curing process, as long as the low temperature resistant epoxy resin can completely wrap the rare earth barium copper oxide block material. The present invention can further improve the mechanical properties of the rare earth barium copper oxide block material by curing the rare earth barium copper oxide block material with a low temperature resistant epoxy resin.

[0062] The present invention performs an oxidation annealing heat treatment on the REBCO superconducting layer to restore the superconducting performance lost during the stripping process, thereby making it have good superconducting performance; by performing particle irradiation on the REBCO superconducting layer, pinning centers can be introduced into the REBCO superconducting layer to improve its critical current density under a magnetic field; finally, epoxy resin is used for curing to improve the mechanical strength.

[0063] The method for preparing a rare earth barium copper oxide bulk material provided by the present invention separates the REBCO superconducting layer from the tape and stacks them to form a bulk material. This significantly reduces the bulk material's volume, increases the engineering current density, facilitates magnetic flux penetration, and thus achieves a higher trapping field. Furthermore, compared to superconducting bulk materials and bulk materials formed from stacked tapes, the individual REBCO superconducting layers are very thin and unobstructed by other materials on the surface. Therefore, they are more suitable for introducing pinning centers within the film using particle irradiation, thereby improving its critical current density under magnetic fields. Furthermore, compared to directly stacking superconducting tapes to form a bulk material, stacking only REBCO superconducting layers to form a bulk material effectively reduces eddy current losses caused by the metal layer in the tape.

[0064] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0065] Example 1

[0066] A method for separating a REBCO superconducting layer from a REBCO tape, comprising the following steps:

[0067] (1) removing the metal protective layer from the REBCO strip to obtain a REBCO strip without the metal protective layer;

[0068] (2) overlapping the metal-free REBCO strip obtained in step (1) with the silver strip, and placing the overlapping strip between two rollers for hot pressing to obtain a silver strip / REBCO strip; the length and width of the silver strip are the same as those of the metal-free REBCO strip, and the thickness of the silver strip is 100 μm; the distance between the center axes of the two rollers is ≥10 cm, and the temperature of the rollers is 800° C.; the temperature of the hot pressing is 800° C., the pressure of the hot pressing is 10 MPa, the travel speed of the metal-free REBCO strip and the silver strip during the hot pressing is 0.1 m / min, and the hot pressing atmosphere is an oxygen atmosphere;

[0069] (3) keeping the silver ribbon / REBCO ribbon obtained in step (2) straight, and then bending and peeling off the metal alloy base ribbon and the buffer layer from one end to obtain a silver ribbon / silver layer / REBCO superconducting layer; the bending radius during the bending and peeling is greater than 5 mm;

[0070] (4) Etching the silver ribbon and silver layer in the silver ribbon / silver layer / REBCO superconducting layer obtained in step (3) with a silver etchant to obtain a REBCO superconducting layer.

[0071] The REBCO superconducting layer obtained in Example 1 is complete without any breakage, and no superconducting layer remains on the original superconducting tape.

[0072] Example 2

[0073] A method for separating a REBCO superconducting layer from a REBCO tape, comprising the following steps:

[0074] (1) removing the metal protective layer from the REBCO strip to obtain a REBCO strip without the metal protective layer;

[0075] (2) overlapping the metal-free REBCO strip obtained in step (1) and the silver strip, and placing them between two rollers for hot pressing to obtain a silver strip / REBCO strip; the length and width of the silver strip are the same as those of the metal-free REBCO strip, and the thickness of the silver strip is 100 μm; the distance between the center axes of the two rollers is ≥10 cm, and the temperature of the rollers is 960° C.; the temperature of the hot pressing is 960° C., the pressure of the hot pressing is 10 MPa, the travel speed of the metal-free REBCO strip and the silver strip during the hot pressing is 1 m / min, and the hot pressing atmosphere is an oxygen atmosphere;

[0076] (3) keeping the silver ribbon / REBCO ribbon obtained in step (2) straight, and then bending and peeling off the metal alloy base ribbon and the buffer layer from one end to obtain a silver ribbon / silver layer / REBCO superconducting layer; the bending radius during the bending and peeling is greater than 5 mm;

[0077] (4) Etching the silver ribbon and silver layer in the silver ribbon / silver layer / REBCO superconducting layer obtained in step (3) with a silver etchant to obtain a REBCO superconducting layer.

[0078] The REBCO superconducting layer obtained in Example 2 is complete without any breakage, and no superconducting layer remains on the original superconducting tape.

[0079] Example 3

[0080] A method for separating a REBCO superconducting layer from a REBCO tape, comprising the following steps:

[0081] (1) removing the metal protective layer from the REBCO strip to obtain a REBCO strip without the metal protective layer;

[0082] (2) overlapping the metal-free REBCO strip obtained in step (1) with the silver strip, and placing the overlapping strip between two rollers for hot pressing to obtain a silver strip / REBCO strip; the length and width of the silver strip are the same as those of the metal-free REBCO strip, and the thickness of the silver strip is 100 μm; the distance between the center axes of the two rollers is ≥10 cm, and the temperature of the rollers is 400° C.; the temperature of the hot pressing is 400° C., the pressure of the hot pressing is 10 MPa, the travel speed of the metal-free REBCO strip and the silver strip during the hot pressing is 0.001 m / min, and the hot pressing atmosphere is an oxygen atmosphere;

[0083] (3) keeping the silver ribbon / REBCO ribbon obtained in step (2) straight, and then bending and peeling off the metal alloy base ribbon and the buffer layer from one end to obtain a silver ribbon / silver layer / REBCO superconducting layer; the bending radius during the bending and peeling is greater than 5 mm;

[0084] (4) Etching the silver ribbon and silver layer in the silver ribbon / silver layer / REBCO superconducting layer obtained in step (3) with a silver etchant to obtain a REBCO superconducting layer.

[0085] The REBCO superconducting layer obtained in Example 3 is complete without any breakage, and no superconducting layer remains on the original superconducting tape.

[0086] Comparative Example 1

[0087] A method for separating a REBCO superconducting layer from a REBCO tape, comprising the following steps:

[0088] (1) removing the metal protective layer from the REBCO strip to obtain a REBCO strip without the metal protective layer;

[0089] (2) overlapping the metal-free REBCO strip obtained in step (1) and the silver strip, and placing them between two rollers for hot pressing to obtain a silver strip / REBCO strip; the length and width of the silver strip are the same as those of the metal-free REBCO strip, and the thickness of the silver strip is 100 μm; the distance between the center axes of the two rollers is ≥10 cm, and the temperature of the rollers is 1000° C.; the temperature of the hot pressing is 1000° C., the pressure of the hot pressing is 10 MPa, the travel speed of the metal-free REBCO strip and the silver strip during hot pressing is 1 m / min, and the hot pressing atmosphere is an oxygen atmosphere;

[0090] (3) keeping the silver ribbon / REBCO ribbon obtained in step (2) straight, and then bending and peeling off the metal alloy base ribbon and the buffer layer from one end to obtain a silver ribbon / silver layer / REBCO superconducting layer; the bending radius during the bending and peeling is greater than 5 mm;

[0091] (4) Etching the silver ribbon and silver layer in the silver ribbon / silver layer / REBCO superconducting layer obtained in step (3) with a silver etchant to obtain a REBCO superconducting layer.

[0092] The REBCO superconducting layer obtained in Comparative Example 1 was incomplete, with some cracks and partial peeling of the REBCO superconducting layer. The superconducting layer remained in some areas of the original superconducting tape. This was because the silver had melted at 1000°C, and the silver tape was discontinuous or broken after heat treatment, resulting in the final superconducting layer being unable to be completely peeled off or being broken at a certain point.

[0093] Comparative Example 2

[0094] A method for separating a REBCO superconducting layer from a REBCO tape, comprising the following steps:

[0095] (1) removing the metal protective layer from the REBCO strip to obtain a REBCO strip without the metal protective layer;

[0096] (2) overlapping the metal-free REBCO strip obtained in step (1) and the silver strip, and placing them between two rollers for hot pressing to obtain a silver strip / REBCO strip; the length and width of the silver strip are the same as those of the metal-free REBCO strip, and the thickness of the silver strip is 100 μm; the distance between the center axes of the two rollers is ≥10 cm, and the temperature of the rollers is 300° C.; the temperature of the hot pressing is 300° C., the pressure of the hot pressing is 10 MPa, the travel speed of the metal-free REBCO strip and the silver strip during hot pressing is 0.001 m / min, and the hot pressing atmosphere is an oxygen atmosphere;

[0097] (3) keeping the silver ribbon / REBCO ribbon obtained in step (2) straight, and then bending and peeling off the metal alloy base ribbon and the buffer layer from one end to obtain a silver ribbon / silver layer / REBCO superconducting layer; the bending radius during the bending and peeling is greater than 5 mm;

[0098] (4) Etching the silver ribbon and silver layer in the silver ribbon / silver layer / REBCO superconducting layer obtained in step (3) with a silver etchant to obtain a REBCO superconducting layer.

[0099] The REBCO superconducting layer obtained in Comparative Example 2 was incomplete, and the superconducting layer remained in many areas on the original superconducting tape. This was because the diffusion connection between the silver tape and the silver layer was incomplete at 300°C, resulting in many pores and making it impossible to completely peel off the superconducting layer.

[0100] Application Example 1

[0101] A method for preparing a rare earth barium copper oxide bulk material comprises the following steps:

[0102] 1) The REBCO superconducting layer prepared in Example 1 was subjected to oxidation annealing heat treatment and particle irradiation in sequence to obtain a high-performance REBCO superconducting layer; the oxidation annealing heat treatment temperature was 500°C, the oxidation annealing heat treatment time was 1 hour, and the oxidation annealing heat treatment atmosphere was an oxygen atmosphere; the particle irradiation method was: using 60keV protons at 10 15 p / cm 2 irradiation with a dose of

[0103] 2) Cutting and stacking the high-performance REBCO superconducting layers obtained in step 1) in sequence to obtain rare earth barium copper oxide bulk materials, and then curing the rare earth barium copper oxide bulk materials with a low-temperature resistant epoxy resin.

[0104] In combination with Example 1 and Application Example 1, the flow chart of the present invention for preparing rare earth barium copper oxide bulk material using REBCO strip is as follows: Figure 1 shown. Figure 1 In the figure, 1 is a silver ribbon, 2 is a REBCO ribbon, 21 is a silver layer, 22 is a REBCO superconducting layer, 23 is a buffer layer, 24 is a metal alloy substrate, 3 is a roller, 4 is a silver ribbon / silver layer / REBCO superconducting layer, 5 is a silver etchant, 6 is a REBCO superconducting layer, 7 is an oxidation annealing heat treatment, 8 is particle irradiation, 9 is a stacked superconducting block, and 10 is a low-temperature resistant epoxy resin.

[0105] Depend on Figure 1 It can be seen that the silver layer in the REBCO strip without a metal protective layer is overlapped with the silver ribbon and then pressurized by two rollers to diffusely connect the silver layer and the silver ribbon. Then, the stripping process is carried out to remove the metal alloy base strip and the buffer layer in the silver ribbon / silver layer / REBCO superconducting layer strip by bending and stripping to obtain the silver ribbon / silver layer / REBCO superconducting layer 4. Then, the silver ribbon / silver layer / REBCO superconducting layer 4 enters the silver etchant 5 to remove the silver ribbon and silver layer to obtain the REBCO superconducting layer 6. The REBCO superconducting layer 6 is sequentially subjected to oxidation annealing heat treatment 7, particle irradiation 8, cutting and stacking to obtain a stacked superconducting block 9. Finally, the stacked superconducting block is cured with a low-temperature resistant epoxy resin 10 to obtain the desired rare earth barium copper oxide block.

[0106] Application Example 2

[0107] A method for preparing a rare earth barium copper oxide bulk material comprises the following steps:

[0108] 1) The REBCO superconducting layer prepared in Example 2 was subjected to oxidation annealing heat treatment and particle irradiation in sequence to obtain a high-performance REBCO superconducting layer; the oxidation annealing heat treatment temperature was 600°C, the oxidation annealing heat treatment time was 0.5h, and the oxidation annealing heat treatment atmosphere was an oxygen atmosphere; the particle irradiation method was: using 60keV protons at 10 15 p / cm2 irradiation with a dose of

[0109] 2) Cutting and stacking the high-performance REBCO superconducting layers obtained in step 1) in sequence to obtain rare earth barium copper oxide bulk materials, and then curing the rare earth barium copper oxide bulk materials with a low-temperature resistant epoxy resin.

[0110] Application Example 3

[0111] A method for preparing a rare earth barium copper oxide bulk material comprises the following steps:

[0112] 1) The REBCO superconducting layer prepared in Example 3 was subjected to oxidation annealing heat treatment and particle irradiation in sequence to obtain a high-performance REBCO superconducting layer; the oxidation annealing heat treatment temperature was 400°C, the oxidation annealing heat treatment time was 2 hours, and the oxidation annealing heat treatment atmosphere was an oxygen atmosphere; the particle irradiation method was: using 60keV protons at 10 15 p / cm 2 irradiation with a dose of

[0113] 2) Cutting and stacking the high-performance REBCO superconducting layers obtained in step 1) in sequence to obtain rare earth barium copper oxide bulk materials, and then curing the rare earth barium copper oxide bulk materials with a low-temperature resistant epoxy resin.

[0114] Comparative Application Example 1

[0115] The REBCO tape in step (1) of Example 1.

[0116] Figure 2 VI curves of the REBCO superconducting layer prepared in Example 1 of the present invention and the original unirradiated REBCO tape provided in Comparative Application Example 1. Figure 2 It can be seen that the REBCO superconducting layer provided by the present invention for preparing rare earth barium copper oxide bulk material can retain more than 90% of the critical current of the REBCO tape and has good conductivity, which proves the feasibility of separating the REBCO superconducting layer.

[0117] The critical current density of the high performance REBCO superconducting layer prepared in Example 1 and the REBCO tape provided in Comparative Application Example 1 were tested, and the obtained Jc-B curves are shown as follows: Figure 3 As shown. Figure 3 It can be seen that the Jc of the irradiated REBCO superconducting layer is nearly doubled compared to that of the REBCO tape, indicating that the REBCO superconducting layer provided by the present invention can significantly increase its critical current density under a magnetic field, and that preparing it into a rare earth barium copper oxide bulk material can obviously further improve the performance of the bulk material.

[0118] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for separating a REBCO superconducting layer from a REBCO tape, comprising the following steps: (1) Removing the metal protective layer from the REBCO strip to obtain a REBCO strip without a metal protective layer; (2) hot pressing a composite silver strip on the silver layer surface of the REBCO strip without a metal protective layer obtained in step (1) to obtain a silver strip / REBCO strip; (3) peeling off the metal alloy base tape and the buffer layer from the silver tape / REBCO tape obtained in step (2) to obtain a silver tape / silver layer / REBCO superconducting layer; the peeling method is to keep the silver tape / REBCO tape straight and then bend and peel off the metal alloy base tape and the buffer layer from one end; the bending radius during the bending peeling is greater than 5 mm; (4) etching the silver ribbon and silver layer in the silver ribbon / silver layer / REBCO superconducting layer obtained in step (3) to obtain a REBCO superconducting layer; In step (2), the hot pressing temperature is 400-960° C., the hot pressing pressure is 1-50 MPa, and the running speed of the REBCO strip without a metal protective layer and the silver strip during hot pressing is 0.001-1 m / min.

2. The method according to claim 1, characterized in that The hot pressing in step (2) is carried out in a roller.

3. The method according to claim 1, characterized in that The etching solution used in step (4) is a silver etchant.

4. A REBCO superconducting layer prepared by the method according to any one of claims 1 to 3.

5. A rare earth barium copper oxide bulk material, prepared by the REBCO superconducting layer prepared by the method according to any one of claims 1 to 3 or the REBCO superconducting layer according to claim 4.

6. The method for preparing the rare earth barium copper oxide bulk material according to claim 5, comprising the following steps: 1) subjecting the REBCO superconducting layer to oxidation annealing heat treatment and particle irradiation in sequence to obtain a REBCO superconducting layer; 2) Cutting and stacking the REBCO superconducting layers obtained in step 1) in sequence to obtain rare earth barium copper oxide bulk materials.

7. The preparation method according to claim 6, characterized in that In the step 1), the temperature of the oxidation annealing heat treatment is 350-600° C., the time of the oxidation annealing heat treatment is 0.5-2 hours, and the atmosphere of the oxidation annealing heat treatment is an oxygen atmosphere.

8. The preparation method according to claim 6, characterized in that The particle irradiation method in step 1) is: using 60-300 keV protons at 10 14 ~10 17 p / cm 2 doses of irradiation.

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