A Post-Rolling Heat Treatment Method for SmFeAsO1-xFx Superconducting Tape

Abstract

The application relates to a SmFeAsO 1‑x F x A post-rolling heat treatment method of a superconducting tape, by imitating the existing SmFeAsO 1‑x F x A block sintering process method, by imitating the existing SmFeAsO 1‑x F x A tape is placed in SmFeAsO 1‑x F x The powder is filled into a Nb tube and sealed at both ends, and then sealed in a stainless steel tube for heat treatment, so as to improve the superconducting transition temperature (T c ) of the tape and inhibit the loss of F elements of the tape. Compared with the prior art, the application does not need to additionally calculate the SmFeAsO 1‑x F x The mass of the powder is simple and convenient to operate; and the SmFeAsO 1‑x F x The powder can be prepared together when the tape is prepared, and does not need to be prepared separately; a series of Sm1111 tapes are prepared by adopting a powder in place (PIT) method, and a new post-rolling heat treatment (PRS) process is adopted, so that the decrease of T c is relieved.

Description

Technical Field

[0001] This invention relates to the field of superconducting tape manufacturing, and in particular to a SmFeAsO 1-x F x Heat treatment method after rolling of superconducting tape. Background Technology

[0002] Iron-based superconductors were first discovered by Hideo Hosono's group in early 2008, sparking a new wave of research into superconducting materials. Currently, SmFeAsO... 1-x F x The highest superconducting transition temperature (T) in iron-based superconductors c The temperature has reached 55K. Compared with traditional superconducting materials, iron-based superconductors have advantages such as high transition temperature, large upper critical field, and low dependence of the critical current on a strong magnetic field; compared with oxide high-temperature superconducting materials, iron-based superconductors have low anisotropy and simple fabrication process. Due to the significant application prospects of iron-based superconductors, the preparation of iron-based superconducting materials has received widespread international attention. Currently, the fabrication of superconducting wires and tapes of iron-based superconductors has begun.

[0003] Currently, the powder-in-tube (PIT) method is the primary method for preparing SmFeAsO. 1-x F x The mainstream technology for iron-based superconducting wires / strips. This technology involves loading superconducting precursor powder into a metal tube, processing it to the designed wire / strip dimensions through forging, drawing, and rolling processes, and then performing heat treatment to obtain the superconducting wire / strip. (SmFeAsO) 1-x F x The superconductivity of superconducting materials is introduced by the doping of sulfur (F), and deviations from the optimal doping point of F will lead to a decrease or loss of superconductivity. Currently, superconducting tapes produced by rotary forging and drawing undergo significant F loss during post-rolling heat treatment (PRS). Both the commonly used high-temperature short-time and low-temperature long-time PRS methods result in tapes with severely degraded superconductivity due to substantial F loss. c A significant decrease. Moreover, this problem cannot be solved simply by increasing the nominal F content, as an excessively high nominal F content would significantly increase the proportion of impurities. Furthermore, the two problems mentioned above are closely related, SmFeAsO 1-x F x The content of impurity phases in polycrystalline samples is also related to the amount of F doping in the samples. Under the same synthesis conditions, there are very few impurity phases in F-free SmFeAsO polycrystalline samples, while as the amount of F doping increases, impurity phases such as SmAs and SmOF will increase sharply.

[0004] Chinese patent CN103943280B discloses a REFeAsO 1-x F xThe preparation method of iron-based superconducting wires or strips includes the following steps: 1. Preparation of REFeAsO 1-x F x 1. A powder compact is prepared by uniformly mixing powder and Sn powder; 2. The powder compact is heat-treated under an argon atmosphere; 3. The heat-treated powder compact is crushed and ground to obtain superconducting precursor powder; 4. A composite is prepared; 5. The composite is forged and drawn to form wire; 6. The wire is heat-treated to obtain REFeAsO 1-x F x Superconducting wire; or rolling the wire into strip and then heat-treating it to obtain REFeAsO 1-x F x Superconducting tapes, by using REFeAsO 1-x F x The method of heat treatment after mixing superconducting powder and Sn powder into a compact improved the superconducting precursor powder and increased REFeAsO 1- x F x The critical current density for transmission of iron-based superconducting wires / strips was determined, but the method used a high-temperature, short-time heat treatment after rolling, which led to the loss of fluorine (F) in the strip during the heat treatment process, resulting in a significant decrease in the superconducting transition temperature of the strip. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a SmFeAsO 1-x F x Post-rolling heat treatment methods for superconducting tapes, and existing processes for SmFeAsO 1-x F x During the heat treatment of bulk materials, there was no significant loss of fluorine (F) element, while the heat treatment of wire and strip materials resulted in severe F element loss. This invention analyzes that the reason for this may be due to the SmFeAsO2 content during the sintering of bulk materials. 1-x F x The total mass is large and confined within a small enclosed space, so even a small percentage of fluorine loss can generate a significant fluorine partial pressure, inhibiting further fluorine loss. However, during heat treatment, the SmFeAsO contained in the strip... 1-x F x The total mass is small, while the volume of the quartz tube is large. Therefore, after the loss of fluorine (F), a high partial pressure of F cannot be generated to suppress further loss of F. Based on this, this invention hypothesizes that if there is sufficient partial pressure of F in the space where the strip is located during heat treatment, the loss of F in the strip can be suppressed. By imitating existing SmFeAsO4... 1-x F x The bulk sintering process involves sintering SmFeAsO2. 1-x F x Strip placed in SmFeAsO1-x F x Nb tubes are filled with powder and both ends are sealed. The tubes are then sealed in a stainless steel tube and heat-treated to improve the T-value of the wire and strip. c And suppress the loss of F element in the strip.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A type of SmFeAsO 1-x F x A method for heat treatment of superconducting tape after rolling, comprising the following steps:

[0008] S1. Under an inert atmosphere, SmFeAsO 1-x F x Superconducting material powder and Sn powder are mixed evenly to obtain superconducting precursor powder;

[0009] S2. Under an inert atmosphere, the superconducting precursor powder obtained in step S1 is loaded into a metal tube, and then SmFeAsO is added. 1- x F x A superconducting tape is embedded in the superconducting precursor powder, and then both ends of the metal tube are sealed with metal plugs to obtain a composite.

[0010] S3. Seal the composite obtained in step S2 into a stainless steel tube and place the stainless steel tube under an argon atmosphere for heat treatment.

[0011] S4. Under an inert atmosphere, remove the SmFeAsO from the stainless steel tube. 1-x F x The superconducting tape is then ground and polished to complete the process.

[0012] Furthermore, in step S1, SmFeAsO 1-x F x Superconducting material powder and Sn powder are mixed in a mass ratio of 1:0.03 to 0.1.

[0013] Furthermore, in step S1, the SmFeAsO used 1-x F x In superconducting material powder, x = 0.16 to 0.24.

[0014] Furthermore, in step S2, the metal tube is an Nb tube, and the metal plug is made of iron.

[0015] Furthermore, in step S2, the amount of superconducting precursor powder used satisfies the following conditions: it completely fills the metal tube, and SmFeAsO 1-x F x The superconducting tape is completely embedded in the superconducting precursor powder.

[0016] Furthermore, in step S3, the heat treatment process is as follows: holding at a temperature of 850°C for 3 to 30 hours, and then cooling with the furnace.

[0017] Furthermore, in step S3, the composite is sealed into a stainless steel tube by argon arc welding, and the sealing of the stainless steel tube is completed under an inert atmosphere.

[0018] Furthermore, in step S4, SmFeAsO 1-x F x The specific process for removing the superconducting tape is as follows: the stainless steel tube is cut open, the composite is removed, and then the metal tube is cut open to remove the SmFeAsO3 containing the superconducting precursor powder. 1-x F x Superconducting tape. Furthermore, in step S4, the metal tube is cut open using a tube cutter in a circumferential manner.

[0019] Furthermore, in step S2, the SmFeAsO 1-x F x The length of the superconducting tape is 1.5cm or 5cm, SmFeAsO 1- x F x The superconducting tape has a width of 4-4.5 mm and a thickness of 0.6-0.67 mm, and a length of 1.5 cm for SmFeAsO. 1-x F x The superconducting tape corresponds to a weight of 4g of SmFeAsO 1-x F x Superconducting material powder, 5cm long SmFeAsO 1-x F x 15g of SmFeAsO was weighed as superconducting tape. 1-x F x Superconducting material powder.

[0020] Compared with the prior art, the advantages of the present invention are as follows:

[0021] 1. This invention does not require additional calculation of the SmFeAsO content of the wrapping strip. 1-x F x The powder is of high quality and the operation is simple and convenient. Furthermore, SmFeAsO 1-x F x The powder can be prepared together with the strip material and does not need to be prepared separately;

[0022] 2. This invention utilizes a pre-position PIT method to prepare a series of Sm1111 tapes, employing a novel PRS process. During the prolonged sintering process, fluorine (F) loss was suppressed, and the decrease in superconducting transition temperature was significantly mitigated. MPMS magnetic measurements revealed that the superconducting transition temperature of the tapes after PRS was significantly higher than that of previously reported Sm1111 magnetic tapes. Attached Figure Description

[0023] Figure 1 This is a specific schematic diagram of the present invention;

[0024] Figure 2 Image showing the dependence of magnetic susceptibility on temperature for strips subjected to high-temperature short-time and low-temperature long-time rolling followed by heat treatment (PRS) and strips from Example 1.

[0025] Figure 3 SmFeAsO as described in Embodiment 1 of the present invention 1-x F x X-ray diffraction pattern of the superconducting core of the superconducting tape.

[0026] The reference numerals in the attached figures are explained as follows: 1. Stainless steel tube; 2. Metal plug; 3. Superconducting precursor powder; 4. SmFeAsO 1-x F x 5. Superconducting tape; 6. Metal tube. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0028] In the following embodiments, SmFeAsO is used 1-x F x Superconducting tape, SmFeAsO 1-x F x All superconducting material powders were prepared in-house. The specific preparation process is as follows:

[0029] SmFeAsO 1-x F x The superconducting material powder uses Sm powder, Fe powder, As powder, Fe2O3 powder and SmF3 powder as raw materials. The specific addition ratio of Sm powder, Fe powder, As powder, Fe2O3 powder and SmF3 powder is based on the molar ratio of each element Sm:Fe:As:O:F = 1:1:1:0.76~0.84:0.16~0.24. The specific mass required for each raw material is obtained by calculation. The powder must not come into contact with air throughout the preparation process.

[0030] Mix the reaction ingredients in proportion in a glove box, and grind the ingredients thoroughly into a uniform powder using a mortar and pestle.

[0031] The raw materials were ball-milled for an extended period using a planetary ball mill until they were thoroughly mixed. The mixed powder was then loaded into a niobium tube, and both ends were sealed with iron plugs. The niobium tube was then sealed into an iron tube using argon arc welding. The iron tube was then placed in an argon-protected tube furnace for heat treatment at 1100℃ for 1800 minutes to finally obtain SmFeAsO. 1-x F x Superconducting bulk material, after grinding, yields SmFeAsO 1-x F x Superconducting material powder;

[0032] SmFeAsO 1-x F x The fabrication of superconducting tapes first involves SmFeAsO 1-x F x Superconducting material powder is loaded into a silver tube with an inner diameter of 5 mm. Metal plugs are used to seal both ends of the silver tube, and hydraulic clamps are used to gently hold the plugs in place, preventing them from easily slipping out. This step yields a composite of powder and metal tube. The composite is then placed in a rotary forging mill, and its diameter is reduced by continuously shrinking the inner diameter of the die. Next, the inner diameter of the strip is further reduced by drawing, and the composite is lengthened. Finally, after multiple rolling passes, SmFeAsO is obtained. 1-x F x Superconducting tape.

[0033] Unless otherwise specified, all other raw materials or processing techniques are commercially available materials or conventional processing techniques in the field.

[0034] like Figure 1 As shown, the specific steps of the present invention are as follows:

[0035] S1. Under an inert atmosphere, SmFeAsO 1-x F x Superconducting material powder and Sn powder are mixed evenly to obtain superconducting precursor powder 3;

[0036] S2. Under an inert atmosphere, the superconducting precursor powder 3 obtained in step S1 is loaded into a metal tube 5, and then SmFeAsO is added. 1-x F x The superconducting tape 4 is embedded in the superconducting precursor powder 3, and then the two ends of the metal tube 5 are sealed with metal plugs 2 to obtain a composite.

[0037] S3. Seal the composite obtained in step S2 into stainless steel tube 1, and place stainless steel tube 1 under an argon atmosphere for heat treatment.

[0038] S4. Under an inert atmosphere, remove the SmFeAsO from stainless steel tube 1. 1-x F x Superconducting tape 4, grind and polish, and it is complete.

[0039] The present invention will be described in more detail by referring to the above process and listing the following embodiments.

[0040] Example 1

[0041] like Figure 1-3 As shown, a SmFeAsO 1-x F x A method for heat treatment of superconducting tape after rolling, comprising the following steps:

[0042] Step 1: Under an inert atmosphere, roll the SmFeAsO 0.8 F 0.2 The superconducting tape was cut into two 1.5cm lengths;

[0043] Step 2: Under an inert atmosphere, weigh 4.356g of SmFeAsO according to the length of the cut strip. 0.8 F 0.2 Superconducting material powder, SmFeAsO 0.8 F 0.2 Superconducting material powder and Sn powder were weighed at a mass ratio of 1:0.1 and mixed evenly to obtain superconducting precursor powder.

[0044] Step 3: Under an inert atmosphere, the superconducting precursor powder obtained in Step 2 is loaded into an Nb tube, and the tape cut in Step 1 is embedded in the superconducting precursor powder. Then, the two ends of the Nb tube are sealed with iron plugs to obtain a composite.

[0045] Step 4: Seal the composite obtained in Step 3 into a stainless steel tube by argon arc welding;

[0046] Step 5: The stainless steel tube obtained in Step 4 is heat-treated in an argon atmosphere; the heat treatment process is as follows: the tube is held at 850°C for 15 hours, and then cooled in the furnace.

[0047] Step 6: Under an inert atmosphere, cut open the stainless steel tube from Step 5, remove the composite obtained in Step 3, and cut open the Nb tube to remove the strip containing the superconducting precursor powder. Then, obtain SmFeAsO by grinding and polishing. 0.8 F 0.2 Superconducting tape;

[0048] The superconducting transition temperature of this example was measured using the integrated magnetic measurement system (MPMS3) of the Institute of Electrical Engineering, Chinese Academy of Sciences. Measurement results: The SmFeAsO2 prepared in this example... 0.8 F 0.2 The superconducting transition temperature of the superconducting tape reached 52.5K. The superconducting transition temperature of the tape using the new process has been greatly improved, only slightly lower than that of the Sm1111 superconducting bulk material.

[0049] Example 2

[0050] A type of SmFeAsO 1-x F x A method for heat treatment of superconducting tape after rolling, comprising the following steps:

[0051] Step 1: Under an inert atmosphere, roll the SmFeAsO 0.76 F 0.24 The superconducting tape was cut into two 1.5cm lengths;

[0052] Step 2: Under an inert atmosphere, weigh 4.142g of SmFeAsO according to the length of the cut strip. 0.76 F 0.24 Superconducting material powder, SmFeAsO 0.76 F 0.24 The superconducting material powder and Sn powder were weighed at a mass ratio of 1:0.1 and mixed evenly.

[0053] Step 3: Under an inert atmosphere, the superconducting precursor powder obtained in Step 2 is loaded into an Nb tube, and the tape cut in Step 1 is embedded in the superconducting precursor powder. Then, the two ends of the Nb tube are sealed with iron plugs to obtain a composite.

[0054] Step 4: Seal the composite obtained in Step 3 into a stainless steel tube by argon arc welding;

[0055] Step 5: The stainless steel tube obtained in Step 4 is heat-treated in an argon atmosphere; the heat treatment process is as follows: the tube is held at 850°C for 3 hours, and then cooled in the furnace.

[0056] Step 6: Under an inert atmosphere, cut open the stainless steel tube from Step 5, remove the composite obtained in Step 3, and cut open the metal tube to remove the strip containing the superconducting precursor powder. Then, obtain SmFeAsO by grinding and polishing. 0.76 F 0.24 Superconducting tape.

[0057] Example 3

[0058] A type of SmFeAsO 1-x F x A method for heat treatment of superconducting tape after rolling, comprising the following steps:

[0059] Step 1: Under an inert atmosphere, roll the SmFeAsO 0.84 F 0.16 The superconducting tape was cut into two 1.5cm lengths;

[0060] Step 2: Under an inert atmosphere, weigh 3.978g of SmFeAsO according to the length of the cut strip. 0.84 F 0.16 Superconducting material powder, SmFeAsO 0.84 F 0.16 The superconducting material powder and Sn powder were weighed at a mass ratio of 1:0.1 and mixed evenly.

[0061] Step 3: Under an inert atmosphere, the superconducting precursor powder obtained in Step 2 is loaded into an Nb tube, and the tape cut in Step 1 is embedded in the superconducting precursor powder. Then, the two ends of the Nb tube are sealed with iron plugs to obtain a composite.

[0062] Step 4: Seal the composite obtained in Step 3 into a stainless steel tube by argon arc welding;

[0063] Step 5: The stainless steel tube obtained in Step 4 is heat-treated in an argon atmosphere; the heat treatment process is as follows: the tube is held at 850°C for 20 hours, and then cooled in the furnace.

[0064] Step 6: Under an inert atmosphere, cut open the stainless steel tube from Step 5, remove the composite obtained in Step 3, and cut open the metal tube to remove the strip containing the superconducting precursor powder. Then, obtain SmFeAsO by grinding and polishing. 0.84 F 0.16 Superconducting tape.

[0065] Example 4

[0066] A type of SmFeAsO 1-x F x A method for heat treatment of superconducting tape after rolling, comprising the following steps:

[0067] Step 1: Under an inert atmosphere, roll the SmFeAsO 0.82 F 0.18 The superconducting tape was cut into two 1.5cm lengths;

[0068] Step 2: Under an inert atmosphere, weigh 4.232g of SmFeAsO according to the length of the cut strip. 0.82 F 0.18 Superconducting material powder, SmFeAsO 0.82 F 0.18 The superconducting material powder and Sn powder were weighed at a mass ratio of 1:0.1 and mixed evenly.

[0069] Step 3: Under an inert atmosphere, the superconducting precursor powder obtained in Step 2 is loaded into an Nb tube, and the tape cut in Step 1 is embedded in the superconducting precursor powder. Then, the two ends of the Nb tube are sealed with iron plugs to obtain a composite.

[0070] Step 4: Seal the composite obtained in Step 3 into a stainless steel tube by argon arc welding;

[0071] Step 5: The stainless steel tube obtained in Step 4 is heat-treated in an argon atmosphere; the heat treatment process is as follows: the tube is held at 850°C for 30 hours, and then cooled in the furnace.

[0072] Step 6: Under an inert atmosphere, cut open the stainless steel tube from Step 5, remove the composite obtained in Step 3, and cut open the metal tube to remove the strip containing the superconducting precursor powder. Then, obtain SmFeAsO by grinding and polishing. 0.82 F 0.18 Superconducting tape.

[0073] Example 5

[0074] A type of SmFeAsO 1-x F x A method for heat treatment of superconducting tape after rolling, comprising the following steps:

[0075] Step 1: Under an inert atmosphere, roll the SmFeAsO 0.78 F 0.22 The superconducting tape was cut into two 1.5cm lengths;

[0076] Step 2: Under an inert atmosphere, weigh 4.06g of SmFeAsO according to the length of the cut strip. 0.78 F 0.22 Superconducting material powder, SmFeAsO 0.78 F 0.22 The superconducting material powder and Sn powder were weighed at a mass ratio of 1:0.03 and mixed evenly.

[0077] Step 3: Under an inert atmosphere, the superconducting precursor powder obtained in Step 2 is loaded into an Nb tube, and the tape cut in Step 1 is embedded in the superconducting precursor powder. Then, the two ends of the Nb tube are sealed with iron plugs to obtain a composite.

[0078] Step 4: Seal the composite obtained in Step 3 into a stainless steel tube by argon arc welding;

[0079] Step 5: The stainless steel tube obtained in Step 4 is heat-treated in an argon atmosphere; the heat treatment process is as follows: the tube is held at 850°C for 15 hours, and then cooled in the furnace.

[0080] Step 6: Under an inert atmosphere, cut open the stainless steel tube from Step 5, remove the composite obtained in Step 3, and cut open the metal tube to remove the strip containing the superconducting precursor powder. Then, obtain SmFeAsO by grinding and polishing.0.78 F 0.22 Superconducting tape.

[0081] Example 6

[0082] A type of SmFeAsO 1-x F x A method for heat treatment of superconducting tape after rolling, comprising the following steps:

[0083] Step 1: Under an inert atmosphere, roll the SmFeAsO 0.79 F 0.21 The superconducting tape was cut into two 1.5cm lengths;

[0084] Step 2: Under an inert atmosphere, weigh 3.886g of SmFeAsO according to the length of the cut strip. 0.79 F 0.21 Superconducting material powder, SmFeAsO 0.79 F 0.21 The superconducting material powder and Sn powder were weighed at a mass ratio of 1:0.06 and mixed evenly.

[0085] Step 3: Under an inert atmosphere, the superconducting precursor powder obtained in Step 2 is loaded into an Nb tube, and the tape cut in Step 1 is embedded in the superconducting precursor powder. Then, the two ends of the Nb tube are sealed with iron plugs to obtain a composite.

[0086] Step 4: Seal the composite obtained in Step 3 into a stainless steel tube by argon arc welding;

[0087] Step 5: The stainless steel tube obtained in Step 4 is heat-treated in an argon atmosphere; the heat treatment process is as follows: the tube is held at 850°C for 15 hours, and then cooled in the furnace.

[0088] Step 6: Under an inert atmosphere, cut open the stainless steel tube from Step 5, remove the composite obtained in Step 3, and cut open the metal tube to remove the strip containing the superconducting precursor powder. Then, obtain SmFeAsO by grinding and polishing. 0.79 F 0.21 Superconducting tape.

[0089] Example 7

[0090] A type of SmFeAsO 1-x F x A method for heat treatment of superconducting tape after rolling, comprising the following steps:

[0091] Step 1: Under an inert atmosphere, roll the SmFeAsO 0.81 F 0.19 The superconducting tape was cut into two 5cm lengths.

[0092] Step 2: Under an inert atmosphere, weigh 14.345g of SmFeAsO according to the length of the cut strip. 0.81 F 0.19 Superconducting material powder, SmFeAsO 0.81 F 0.19 The superconducting material powder and Sn powder were weighed at a mass ratio of 1:0.1 and mixed evenly.

[0093] Step 3: Under an inert atmosphere, the superconducting precursor powder obtained in Step 2 is loaded into an Nb tube, and the tape cut in Step 1 is embedded in the superconducting precursor powder. Then, the two ends of the Nb tube are sealed with iron plugs to obtain a composite.

[0094] Step 4: Seal the composite obtained in Step 3 into a stainless steel tube by argon arc welding;

[0095] Step 5: The stainless steel tube obtained in Step 4 is heat-treated in an argon atmosphere; the heat treatment process is as follows: the tube is held at 850°C for 15 hours, and then cooled in the furnace.

[0096] Step 6: Under an inert atmosphere, cut open the stainless steel tube from Step 5, remove the composite obtained in Step 3, and cut open the metal tube to remove the strip containing the superconducting precursor powder. Then, obtain SmFeAsO by grinding and polishing. 0.81 F 0.19 Superconducting tape.

[0097] Figure 2 This image shows the temperature dependence of the magnetic susceptibility of the tapes under different PRS processes. The tapes prepared by the 1100℃-50s PRS process and the 300℃-6h PRS process did not have superconducting precursor powder added during the PRS process. c The K values ​​are 37.4 K and 44 K, respectively. The new PRS process, which incorporates superconducting precursor powder, exhibits higher T values. c The temperature was 52.5 K. This phenomenon indicates that the new PRS process has a significant effect on suppressing the loss of fluorine.

[0098] Figure 3 The image shown is the XRD θ-2θ image of Example 1. The XRD pattern reveals that the main phase is Sm1111, and the impurity phases are SmOF, SmAs, SmFe, Ag, and Ag3Sn. The lattice constant is calculated as follows: By comparing the data with previous studies, it was found that the lattice constant of Example 1 is similar to that of SmFeAsO 0.8 F 0.2 The lattice constants are relatively close, indicating that the new PRS process has a significant effect on suppressing the loss of fluorine.

[0099] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A type of SmFeAsO 1-x F x A method for heat treatment after rolling of superconducting tape, characterized in that, The method includes the following steps: S1. Under an inert atmosphere, SmFeAsO 1-x F x Superconducting material powder and Sn powder are mixed evenly to obtain superconducting precursor powder; S2. Under an inert atmosphere, the superconducting precursor powder obtained in step S1 is loaded into a metal tube, and then SmFeAsO is added. 1-x F x A superconducting tape is embedded in the superconducting precursor powder, and then both ends of the metal tube are sealed with metal plugs to obtain a composite. S3. Seal the composite obtained in step S2 into a stainless steel tube and place the stainless steel tube under an argon atmosphere for heat treatment. S4. Under an inert atmosphere, remove the SmFeAsO from the stainless steel tube. 1-x F x The superconducting tape is then ground and polished to complete the process.

2. The SmFeAsO according to claim 1 1-x F x A method for heat treatment after rolling of superconducting tape, characterized in that, In step S1, SmFeAsO 1-x F x Superconducting material powder and Sn powder are mixed in a mass ratio of 1:0.03 to 0.

1.

3. The SmFeAsO according to claim 1 1-x F x A method for heat treatment after rolling of superconducting tape, characterized in that, In step S1, the SmFeAsO used 1-x F x In superconducting material powder, x = 0.16~0.

24.

4. The SmFeAsO according to claim 1 1-x F x A method for heat treatment after rolling of superconducting tape, characterized in that, In step S2, the metal tube is an Nb tube, and the metal plug is an iron plug.

5. The SmFeAsO according to claim 1 1-x F x A method for heat treatment after rolling of superconducting tape, characterized in that, In step S2, the amount of superconducting precursor powder used satisfies the following conditions: it completely fills the metal tube, and SmFeAsO 1-x F x The superconducting tape is completely embedded in the superconducting precursor powder.

6. The SmFeAsO according to claim 1 1-x F x A method for heat treatment after rolling of superconducting tape, characterized in that, In step S3, the heat treatment process is as follows: hold at 850 ℃ for 3 to 30 hours, and then cool with the furnace.

7. The SmFeAsO according to claim 1 1-x F x A method for heat treatment after rolling of superconducting tape, characterized in that, In step S3, the composite is sealed into a stainless steel tube by argon arc welding.

8. The SmFeAsO according to claim 1 1-x F x A method for heat treatment after rolling of superconducting tape, characterized in that, In step S4, SmFeAsO 1-x F x The specific process for removing the superconducting tape is as follows: the stainless steel tube is cut open, the composite is removed, and then the metal tube is cut open to remove the SmFeAsO4 containing the superconducting precursor powder. 1-x F x Superconducting tape.

9. A SmFeAsO according to claim 8 1-x F x A method for heat treatment after rolling of superconducting tape, characterized in that, In step S4, the metal pipe is cut open using a pipe cutter in a circumferential manner.

10. A SmFeAsO according to claim 1 1-x F x A method for heat treatment after rolling of superconducting tape, characterized in that, In step S2, the SmFeAsO 1-x F x The length of the superconducting tape is 1.5 cm or 5 cm, SmFeAsO 1-x F x The superconducting tape has a width of 4-4.5 mm and a thickness of 0.6-0.67 mm.

Images