A (cu,c)-1234 superconducting wire and method of making
By employing cold processing and hot pressing sintering processes, (Cu,C)-1234 superconducting bulk materials synthesized under high temperature and high pressure are prepared into superconducting wires and strips, solving the problem of large-scale application and realizing the industrial production of high-performance superconducting wires and strips.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INST OF ELECTRICAL ENG CHINESE ACAD OF SCI
- Filing Date
- 2026-04-30
- Publication Date
- 2026-06-09
Smart Images
Figure CN122177584A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of superconducting materials technology, and in particular to a (Cu,C)-1234 superconducting wire and tape and its preparation method. Background Technology
[0002] In 1986, the discovery of Cu-based superconductors overturned previous understandings of the superconducting transition temperature (T0). c The cognition of ) . Therefore, a large number of T c Cu-based superconductors with temperatures above liquid nitrogen have been discovered. Among them, Bi-based (Bi-2223, etc.), Tl-based (Tl-2223, etc.), and Hg-based (Hg-1234, etc.) exhibit superior performance due to their higher temperatures. c Above 100 K, these materials were highly anticipated. However, they all have certain problems. The Bi series, due to its irreversible field (H0) at 77 K... irr The temperature of the Fe is extremely low, making high-field applications in the liquid nitrogen temperature range impossible. Furthermore, the Tl and Hg-based systems are severely limited in their practical production due to the highly toxic metals Tl and Hg in their raw materials. In 1994, Cu-based superconductors in the (Cu,C) system were discovered. (Cu,C)-1234 exhibits high T... c It can reach 118 K, and still exhibits a high upper critical field (15 T at 86 K, 5 T at 98 K) above liquid nitrogen temperature. Furthermore, (Cu,C)-1234 has a critical current density (J / L) under self-field at 77 K. c Up to 6.5 × 10 5 A / cm 2 Furthermore, (Cu,C)-1234 is a non-toxic and harmless raw material that does not require rare earth elements. Therefore, compared to traditional Cu-based superconductors, (Cu,C)-1234 is more promising as a superconductor for high-field applications in the liquid nitrogen temperature range, possessing enormous practical potential.
[0003] However, (Cu,C)-1234 superconducting materials require synthesis under high temperature (approximately 1100 °C) and high pressure (approximately 4 GPa). This high-pressure synthesis method can only produce small-sized polycrystalline bulk materials, making it difficult to achieve large-scale applications. Therefore, there is a need to provide a method for processing initial (Cu,C)-1234 superconducting materials into practical superconducting wires and tapes. Summary of the Invention
[0004] To solve the above-mentioned technical problems, the present invention provides a (Cu,C)-1234 superconducting wire and tape and its preparation method.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A method for preparing (Cu,C)-1234 superconducting wire strip, comprising the following steps:
[0007] Step 1: Precursor powder crushing; the initial (Cu,C)-1234 superconducting bulk material is crushed and ground into superconducting precursor powder;
[0008] Step 2: Powder loading; The (Cu,C)-1234 superconducting precursor powder obtained in Step 1 is uniformly loaded into a metal casing, compacted and sealed to obtain a casing filled with precursor powder.
[0009] Step 3: Cold working; The sleeve filled with precursor powder obtained in Step 2 is subjected to cold working to obtain (Cu,C)-1234 superconducting wire strip.
[0010] Step 4: Hot pressing treatment; The (Cu,C)-1234 superconducting wire and tape obtained in Step 3 can be obtained by hot pressing and sintering; The pressure of hot pressing and sintering shall not be less than 500MPa, and the temperature of hot pressing and sintering shall be 200-400℃.
[0011] The initial (Cu,C)-1234 superconducting bulk material is a (Cu,C)-1234 superconducting material prepared by a six-sided top press.
[0012] In step 1, the particle size of the superconducting precursor powder after grinding is 2-20 μm.
[0013] The heating rate of the hot pressing sintering is 3-10 ℃ / min; the holding time of the hot pressing sintering is 1-24 h; and the holding time of the pressure is 1-24 h.
[0014] Hot pressing sintering is carried out in a hot press furnace, and the pressure remains constant during the hot pressing sintering process.
[0015] During the hot pressing sintering process, pressure is applied when the temperature exceeds 100 ℃, and pressure is released when the sample temperature drops to no higher than 200 ℃.
[0016] In step 3, the cold working process specifically includes one or more of the following: rotary forging, drawing, and rolling.
[0017] The process includes, prior to step 2, adding a metal oxide to the (Cu,C)-1234 superconducting precursor powder; the amount of the metal oxide added is no more than 10% of the mass of the (Cu,C)-1234 superconducting precursor powder.
[0018] The metal oxide is Ag₂O.
[0019] A (Cu,C)-1234 superconducting wire strip is prepared by the above-mentioned preparation method of (Cu,C)-1234 superconducting wire strip.
[0020] The beneficial effects of this invention are as follows:
[0021] (1) The present invention uses (Cu,C)-1234 polycrystalline bulk material synthesized under high temperature and high pressure as raw material and prepares (Cu,C)-1234 superconducting wire and tape with transmission performance by hot pressing sintering process.
[0022] (2) The present invention dops metal oxides into the packaging powder of (Cu,C)-1234 superconducting wire and tape, which improves the connectivity of the superconducting core of the (Cu,C)-1234 superconducting wire and tape at low temperature while providing oxidant. Attached Figure Description
[0023] Figure 1 The (Cu,C)-1234 superconducting wire strip with Ag sheath after cold processing is shown in Example 1.
[0024] Figure 2 The (Cu,C)-1234 superconducting tape with Ag sheath after hot pressing and sintering is shown in Example 1.
[0025] Figure 3 The image shows an XRD comparison of the Ag-coated (Cu,C)-1234 superconducting tape prepared in Example 1 and the (Cu,C)-1234 precursor powder.
[0026] Figure 4 The RT curves of the Ag-coated (Cu,C)-1234 superconducting tape prepared in Example 1 are shown.
[0027] Figure 5 The RT curves of the Ni-clad (Cu,C)-1234 superconducting tape prepared in Example 2 are shown.
[0028] Figure 6 The MT curve of the Ni-clad (Cu,C)-1234 superconducting tape prepared in Example 2.
[0029] Figure 7 The RT curves of the Ni-clad (Cu,C)-1234 superconducting tape prepared in Example 3 are shown.
[0030] Figure 8 RT curves of the Ni-clad 1% Ag2O-doped (Cu,C)-1234 superconducting tape prepared in Example 4.
[0031] Figure 9 The MT curve of the Ni-clad 1% Ag2O-doped (Cu,C)-1234 superconducting tape prepared in Example 4.
[0032] Figure 10RT curves of the Ni-clad 1% Ag2O-doped (Cu,C)-1234 superconducting tape prepared in Example 5.
[0033] Figure 11 RT curves of the Ni-clad 3% Ag2O-doped (Cu,C)-1234 superconducting tape prepared in Example 6. Detailed Implementation
[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.
[0035] A method for preparing (Cu,C)-1234 superconducting wire tape includes the following steps:
[0036] Step 1: Precursor powder crushing; the initial (Cu,C)-1234 superconducting polycrystalline bulk material is crushed and ground into superconducting precursor powder;
[0037] Step 2: Powder loading; The (Cu,C)-1234 superconducting precursor powder obtained in Step 1 is uniformly loaded into a metal casing, compacted and sealed to obtain a casing filled with precursor powder.
[0038] Step 3: Cold working; The sleeve filled with precursor powder obtained in Step 2 is subjected to cold working to obtain (Cu,C)-1234 superconducting wire strip.
[0039] Step 4: Hot pressing treatment; The (Cu,C)-1234 superconducting wire strip obtained in Step 3 is subjected to hot pressing sintering to obtain (Cu,C)-1234 superconducting wire strip with superconducting transmission properties;
[0040] This invention uses (Cu,C)-1234 superconducting polycrystalline bulk material with extremely high intrinsic superconductivity as raw material. After cold processing, (Cu,C)-1234 superconducting wire strips were prepared. Then, using a hot-pressing sintering process, (Cu,C)-1234 superconducting wire strips with superconducting transport properties were successfully prepared, verifying the potential for industrial application of (Cu,C)-1234 superconducting materials. The preparation method of this invention can transform high-temperature, high-pressure synthesized (Cu,C)-1234 polycrystalline bulk material into superconducting wire strips with higher industrial application value.
[0041] The (Cu,C)-1234 superconducting material is a high-performance (Cu,C)-1234 superconducting material prepared by a six-sided top press.
[0042] Preferably, in step 1, the (Cu,C)-1234 powder is crushed and ground in a dry air or inert atmosphere glove box.
[0043] Preferably, the particle size of the (Cu,C)-1234 superconducting material after grinding is 2-20 μm.
[0044] Preferably, the heating rate of the hot pressing sintering is 3-10 °C / min.
[0045] Preferably, hot pressing sintering is carried out in a hot press furnace, with a pressure of not less than 500 MPa and a sintering temperature of 200-400 ℃.
[0046] Preferably, the holding time for hot pressing sintering is 1-24 h, and the holding time for pressure is 1-24 h.
[0047] As a preferred embodiment, a step of adding a metal oxide to the (Cu,C)-1234 superconducting precursor powder is included before step 2;
[0048] Preferably, the metal oxide is Ag₂O.
[0049] The amount of the metal oxide added is 0-10% of the (Cu,C)-1234 superconducting precursor powder.
[0050] Example 1
[0051] Step 1: Crushing the precursor powder;
[0052] In dry air, the initial (Cu,C)-1234 superconducting polycrystalline bulk material was placed in a mortar and ground for 30 minutes to break and grind the bulk material into superconducting precursor powder.
[0053] Step 2: Powder loading into tubes;
[0054] Prepare an 8×6 mm pure Ag tube as a wire and strip sheath. In dry air, fill the pure Ag metal sheath with about 1 g of (Cu,C)-1234 superconducting precursor powder obtained in step 1, compact and seal it to obtain an Ag rod filled with precursor powder.
[0055] Step 3: Cold working;
[0056] The Ag rod filled with precursor powder obtained in step 2 is first forged to Φ 3.4 mm, then drawn to Φ 1.8 mm, and finally rolled to a thickness of 0.3 mm (Cu,C)-1234 superconducting wire strip. The forging adopts a processing rate of 15% per pass, the drawing adopts a surface reduction rate of 10% per pass, and the rolling adopts a reduction amount of about 20% per pass.
[0057] Step 4: Hot pressing treatment;
[0058] The (Cu,C)-1234 superconducting wire strip prepared in step 3 was placed in a boron nitride-coated hot-pressing mold. The mold containing the sample was then placed in a hot-pressing furnace under an air atmosphere. During sintering, the sample was heated at a rate of 5 °C / min, the hot-pressing temperature was 360 °C, and the holding time was 2 h. The hot-pressing pressure was set to 500 MPa, and pressure was applied starting when the sample temperature exceeded 100 °C and continued until cooling. Pressure was released when the sample cooled to 200 °C. After hot-pressing sintering, a (Cu,C)-1234 superconducting wire strip with superconducting transport properties was obtained.
[0059] Figure 1 The (Cu,C)-1234 superconducting wire strip with Ag sheathing was prepared by cold processing in Example 1. The strip is approximately 5 mm wide and 0.3 mm thick. Short samples of the (Cu,C)-1234 superconducting wire strip were formed by cutting every 8 cm.
[0060] Figure 2 The example shown is an Ag-clad (Cu,C)-1234 superconducting tape from Example 1, which underwent hot-pressing and sintering. After hot-pressing and sintering, the tape width increased to 6 mm, and the thickness decreased to approximately 0.2 mm.
[0061] Figure 3 The image shows a comparison of the XRD patterns of the Ag-coated (Cu,C)-1234 superconducting tape and the (Cu,C)-1234 precursor powder prepared in Example 1. The superconducting phase of the core wire of the (Cu,C)-1234 superconducting tape after hot pressing and sintering remains consistent with that of the precursor powder, indicating that the superconducting phase of the tape did not deteriorate after processing and sintering.
[0062] Figure 4 RT curves of the Ag-coated (Cu,C)-1234 superconducting tape prepared in Example 1. The initial transition temperature Ti of the sample. c,onset 118 K, zero resistance temperature T c,zero At 30 K, superconducting current transport was achieved.
[0063] Example 2
[0064] Step 1: Crushing the precursor powder;
[0065] In an Ar atmosphere glove box, the initial (Cu,C)-1234 superconducting polycrystalline bulk material was placed in a mortar and ground for 30 minutes to break and grind the bulk material into superconducting precursor powder.
[0066] Step 2: Powder loading into tubes;
[0067] Prepare a 4×3 mm pure Ni tube as a wire and strip sheath. In a glove box under Ar atmosphere, fill about 1 g of (Cu,C)-1234 superconducting precursor powder obtained in step 1 into the pure Ni metal sheath, compact and seal it to obtain a Ni rod filled with precursor powder.
[0068] Step 3: Cold working;
[0069] The Ni rod filled with precursor powder obtained in step 2 is first forged to Φ 3.4 mm, then drawn to Φ 1.8 mm, and finally rolled to a thickness of 0.4 mm as (Cu,C)-1234 superconducting wire strip. The forging adopts a processing rate of 15% per pass, the drawing adopts a surface reduction rate of 10% per pass, and the rolling adopts a reduction amount of about 20% per pass.
[0070] Step 4: Hot pressing treatment;
[0071] The (Cu,C)-1234 superconducting wire strip prepared in step 3 was placed in a boron nitride-coated hot-pressing mold. The mold containing the sample was then placed in a hot-pressing furnace under an air atmosphere. During sintering, the sample was heated at a rate of 5 °C / min, the hot-pressing temperature was 360 °C, and the holding time was 2 h. The hot-pressing pressure was set to 1000 MPa, and pressure was applied starting when the sample temperature exceeded 100 °C, continuing until cooling. Pressure was released when the sample cooled to 180 °C. After hot-pressing sintering, a (Cu,C)-1234 superconducting wire strip with superconducting transport properties was obtained.
[0072] Figure 5 RT curves of the Ni-clad (Cu,C)-1234 superconducting tape prepared in Example 2. The initial transition temperature Ton of the sample. c,onset 118 K, zero resistance temperature T c,zero At 55 K, superconducting current transport was achieved.
[0073] Figure 6 The MT curves for the Ni-clad (Cu,C)-1234 superconducting tape prepared in Example 2. The initial transition temperature Ton of the sample. c,onset At 118 K, the tape exhibits a very obvious diamagnetic signal in the superconducting state.
[0074] Example 3
[0075] Step 1: Crushing the precursor powder;
[0076] In an Ar atmosphere glove box, the initial (Cu,C)-1234 superconducting polycrystalline bulk material was placed in a mortar and ground for 30 minutes to break and grind the bulk material into superconducting precursor powder.
[0077] Step 2: Powder loading into tubes;
[0078] Prepare a 4×3 mm pure Ni tube as a wire and strip sheath. In a glove box under Ar atmosphere, fill about 1 g of (Cu,C)-1234 superconducting precursor powder obtained in step 1 into the pure Ni metal sheath, compact and seal it to obtain a Ni rod filled with precursor powder.
[0079] Step 3: Cold working;
[0080] The Ni rod filled with precursor powder obtained in step 2 is first forged to Φ 3.4 mm, then drawn to Φ 1.8 mm, and finally rolled to a thickness of 0.4 mm as (Cu,C)-1234 superconducting wire strip. The forging adopts a processing rate of 15% per pass, the drawing adopts a surface reduction rate of 10% per pass, and the rolling adopts a reduction amount of about 20% per pass.
[0081] Step 4: Hot pressing treatment;
[0082] The (Cu,C)-1234 superconducting wire strip prepared in step 3 was placed in a boron nitride-coated hot-pressing mold. The mold containing the sample was then placed in a hot-pressing furnace under an air atmosphere. During sintering, the sample was heated at a rate of 5 °C / min, the hot-pressing temperature was 380 °C, and the holding time was 2 h. The hot-pressing pressure was set to 1000 MPa, and pressure was applied starting when the sample temperature exceeded 100 °C, continuing until cooling. Pressure was released when the sample cooled to 200 °C. After hot-pressing sintering, a (Cu,C)-1234 superconducting wire strip with superconducting transport properties was obtained.
[0083] Figure 7 The RT curves are shown for the Ni-clad (Cu,C)-1234 superconducting tape prepared in Example 3. The tests revealed that the initial transition temperature Ton of the sample is... c,onset 118 K, zero resistance temperature T c,zero At 72 K, superconducting current transport was achieved.
[0084] Example 4
[0085] Step 1: Crushing the precursor powder;
[0086] In an Ar atmosphere glove box, the initial (Cu,C)-1234 superconducting polycrystalline bulk material was placed in a mortar and ground for 30 minutes to break and grind the bulk material into superconducting precursor powder. Ag2O powder with a mass ratio of 1% was weighed and added to the ground (Cu,C)-1234 powder, and ground again for 30 minutes to mix the (Cu,C)-1234 powder and the doped Ag2O powder evenly.
[0087] Step 2: Powder loading into tubes;
[0088] Prepare a 4×3 mm pure Ni tube as a wire and strip sheath. In a glove box under Ar atmosphere, fill the pure Ni metal sheath with about 1 g of 1% Ag2O-doped (Cu,C)-1234 superconducting precursor powder obtained in step 1, compact and seal it to obtain a Ni rod filled with precursor powder.
[0089] Step 3: Cold working;
[0090] The Ni rod filled with precursor powder obtained in step 2 is first forged to Φ 3.4 mm, then drawn to Φ 1.8 mm, and finally rolled to a thickness of 0.4 mm as (Cu,C)-1234 superconducting wire strip. The forging adopts a processing rate of 15% per pass, the drawing adopts a surface reduction rate of 10% per pass, and the rolling adopts a reduction amount of about 20% per pass.
[0091] Step 4: Hot pressing treatment;
[0092] The 1% Ag₂O-doped (Cu,C)-1234 superconducting tape prepared in step 3 was placed in a boron nitride-coated hot-pressing mold. The mold containing the sample was then placed in a hot-pressing furnace under an air atmosphere. During sintering, the sample heating rate was 5 °C / min, the hot-pressing temperature was 360 °C, and the holding time was 2 h. The hot-pressing pressure was set to 1000 MPa, and pressure was applied starting when the sample temperature exceeded 100 °C and continued until cooling. Pressure was released when the sample cooled to 200 °C. After hot-pressing sintering, a 1% Ag₂O-doped (Cu,C)-1234 superconducting tape with superconducting transport properties was obtained.
[0093] Figure 8 RT curves of the Ni-clad, 1% Ag₂O-doped (Cu,C)-1234 superconducting tape prepared in Example 4. The initial transition temperature Ti of the sample. c,onset 118 K, zero resistance temperature T c,zero At 50 K, superconducting current transport was achieved.
[0094] Figure 9 MT curves for the Ni-clad, 1% Ag₂O-doped (Cu,C)-1234 superconducting tape prepared in Example 4. The initial transition temperature Ton of the sample. c,onset At 118 K, the tape exhibits a very obvious diamagnetic signal in the superconducting state.
[0095] Compared to Example 2, in Example 4, metal oxides were added to the superconducting precursor powder, from Figure 5 and Figure 8The comparison shows that adding metal oxides can effectively improve the connectivity of superconducting tapes. Specifically, the RT curve of the superconducting tape without added metal oxides (…) Figure 5 Before the superconducting transition, the superconducting tape exhibits the resistive properties of a semiconductor, with resistance increasing as temperature decreases. This indicates poor inter-grain connectivity within the tape. However, the superconducting tape with the addition of metal oxides shows a different RT curve (…). Figure 8 Before the superconducting transition, it exhibited normal metallic resistivity characteristics, and the resistance no longer increased as the temperature decreased; this indicates that the inter-grain connectivity within the strip has improved.
[0096] Example 5
[0097] Step 1: Crushing the precursor powder;
[0098] In an Ar atmosphere glove box, the initial (Cu,C)-1234 superconducting polycrystalline bulk material was placed in a mortar and ground for 30 minutes to break and grind the bulk material into superconducting precursor powder. Ag2O powder with a mass ratio of 1% was weighed and added to the ground (Cu,C)-1234 powder, and ground again for 30 minutes to mix the (Cu,C)-1234 powder and the doped Ag2O powder evenly.
[0099] Step 2: Powder loading into tubes;
[0100] Prepare a 4×3 mm pure Ni tube as a wire and strip sheath. In a glove box under Ar atmosphere, fill the pure Ni metal sheath with about 1 g of 1% Ag2O-doped (Cu,C)-1234 superconducting precursor powder obtained in step 1, compact and seal it to obtain a Ni rod filled with precursor powder.
[0101] Step 3: Cold working;
[0102] The Ni rod filled with precursor powder obtained in step 2 is first forged to Φ 3.4 mm, then drawn to Φ 1.8 mm, and finally rolled to a thickness of 0.4 mm as (Cu,C)-1234 superconducting wire strip. The forging adopts a processing rate of 15% per pass, the drawing adopts a surface reduction rate of 10% per pass, and the rolling adopts a reduction amount of about 20% per pass.
[0103] Step 4: Hot pressing treatment;
[0104] The 1% Ag₂O-doped (Cu,C)-1234 superconducting tape prepared in step 3 was placed in a boron nitride-coated hot-pressing mold. The mold containing the sample was then placed in a hot-pressing furnace under an air atmosphere. During sintering, the sample heating rate was 5 °C / min, the hot-pressing temperature was 370 °C, and the holding time was 2 h. The hot-pressing pressure was set to 1000 MPa, and pressure was applied starting when the sample temperature exceeded 100 °C and continued until cooling. Pressure was released when the sample cooled to 200 °C. After hot-pressing sintering, a 1% Ag₂O-doped (Cu,C)-1234 superconducting tape with superconducting transport properties was obtained.
[0105] Figure 10 RT curves of the Ni-clad, 1% Ag₂O-doped (Cu,C)-1234 superconducting tape prepared in Example 5. The initial transition temperature Ti of the sample. c,onset 118 K, zero resistance temperature T c,zero At 64 K, superconducting current transmission was achieved.
[0106] Example 6
[0107] Step 1: Crushing the precursor powder;
[0108] In an Ar atmosphere glove box, the initial (Cu,C)-1234 superconducting polycrystalline bulk material was placed in a mortar and ground for 30 minutes to break and grind the bulk material into superconducting precursor powder. Ag2O powder with a mass ratio of 3% was weighed and added to the ground (Cu,C)-1234 powder, and ground again for 30 minutes to mix the (Cu,C)-1234 powder and the doped Ag2O powder evenly.
[0109] Step 2: Powder loading into tubes;
[0110] Prepare a 4×3 mm pure Ni tube as a wire and strip sheath. In a glove box under Ar atmosphere, fill the pure Ni metal sheath with about 1 g of 3% Ag2O-doped (Cu,C)-1234 superconducting precursor powder obtained in step 1, compact and seal it to obtain a Ni rod filled with precursor powder.
[0111] Step 3: Cold working;
[0112] The Ni rod filled with precursor powder obtained in step 2 is first forged to Φ 3.4 mm, then drawn to Φ 1.8 mm, and finally rolled to a thickness of 0.4 mm as (Cu,C)-1234 superconducting wire strip. The forging adopts a processing rate of 15% per pass, the drawing adopts a surface reduction rate of 10% per pass, and the rolling adopts a reduction amount of about 20% per pass.
[0113] Step 4: Hot pressing treatment;
[0114] The 3% Ag₂O-doped (Cu,C)-1234 superconducting tape prepared in step 3 was placed in a boron nitride-coated hot-pressing mold. The mold containing the sample was then placed in a hot-pressing furnace under an air atmosphere. During sintering, the sample heating rate was 5 °C / min, the hot-pressing temperature was 360 °C, and the holding time was 2 h. The hot-pressing pressure was set to 1000 MPa, and pressure was applied starting when the sample temperature exceeded 100 °C and continued until cooling. Pressure was released when the sample cooled to 200 °C. After hot-pressing sintering, a 3% Ag₂O-doped (Cu,C)-1234 superconducting tape with superconducting transport properties was obtained.
[0115] Figure 11 RT curves of the Ni-clad, 3% Ag₂O-doped (Cu,C)-1234 superconducting tape prepared in Example 6. The initial transition temperature Ton of the sample. c,onset 118 K, zero resistance temperature T c,zero At 71 K, superconducting current transport was achieved.
[0116] Similarly, from Figure 10 and Figure 11 It can be seen that the superconducting tapes with added metal oxides in Examples 5 and 6 exhibit normal metallic resistance characteristics in their RT curves before the superconducting transition, and the resistance no longer increases with decreasing temperature; this indicates that the connectivity between grains inside the tape has improved.
[0117] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
[0118] The parts of this invention not described in detail are well-known in the art. The above embodiments are provided merely for the purpose of describing the invention and are not intended to limit its scope. The scope of the invention is defined by the appended claims. All equivalent substitutions and modifications made without departing from the spirit and principles of the invention should be covered within its scope.
Claims
1. A method for preparing (Cu,C)-1234 superconducting wire strip, characterized in that, Includes the following steps: Step 1: Precursor powder crushing; the initial (Cu,C)-1234 superconducting bulk material is crushed and ground into superconducting precursor powder; Step 2: Powder loading; The superconducting precursor powder obtained in Step 1 is uniformly loaded into a metal sleeve, compacted and sealed to obtain a sleeve filled with precursor powder. Step 3: Cold working; The sleeve filled with precursor powder obtained in Step 2 is subjected to cold working to obtain (Cu,C)-1234 superconducting wire strip. Step 4: Hot pressing treatment; The (Cu,C)-1234 superconducting wire and tape obtained in Step 3 can be obtained by hot pressing and sintering; wherein, the pressure of hot pressing and sintering is not less than 500MPa, and the temperature of hot pressing and sintering is 200-400℃.
2. The method for preparing (Cu,C)-1234 superconducting wire strip according to claim 1, characterized in that, The initial (Cu,C)-1234 superconducting bulk material is a (Cu,C)-1234 superconducting material prepared by a six-sided top press.
3. The method for preparing (Cu,C)-1234 superconducting wire strip according to claim 1, characterized in that, The particle size of the superconducting precursor powder after grinding in step 1 is 2-20 μm.
4. The method for preparing (Cu,C)-1234 superconducting wire strip according to claim 1, characterized in that, The heating rate of the hot pressing sintering is 3-10 ℃ / min, the holding time of the hot pressing sintering is 1-24 h, and the holding time of the pressure is 1-24 h.
5. The method for preparing (Cu,C)-1234 superconducting wire strip according to claim 1, characterized in that, Hot pressing sintering is carried out in a hot press furnace, and the pressure is kept constant during the hot pressing sintering process.
6. The method for preparing (Cu,C)-1234 superconducting wire strip according to claim 5, characterized in that, During the hot pressing sintering process, pressure is applied when the temperature exceeds 100 ℃, and pressure is released when the sample temperature drops to no higher than 200 ℃.
7. The method for preparing (Cu,C)-1234 superconducting wire strip according to claim 1, characterized in that, The cold working in step 3 specifically includes one or more of the following: rotary forging, drawing, and rolling.
8. The method for preparing (Cu,C)-1234 superconducting wire strip according to any one of claims 1 to 7, characterized in that, Before step 2, a step of adding a metal oxide to the (Cu,C)-1234 superconducting precursor powder is included; the amount of the metal oxide added is no more than 10% of the mass of the (Cu,C)-1234 superconducting precursor powder.
9. The method for preparing (Cu,C)-1234 superconducting wire strip according to claim 8, characterized in that, The metal oxide is Ag₂O.
10. A (Cu,C)-1234 superconducting wire strip, characterized in that, It is prepared by the preparation method of (Cu,C)-1234 superconducting wire and tape according to any one of claims 1 to 9.