CN111768920B - Method for representing processing uniformity of Bi-system high-temperature superconducting wire or strip - Google Patents

Abstract

The invention discloses a method for representing the processing uniformity of a Bi-based high-temperature superconducting wire or strip, which is used for testing the resistance of the Bi-based high-temperature superconducting wire or strip at different positions based on a room-temperature resistance testing principle by a four-wire method and then representing the processing uniformity of the Bi-based high-temperature superconducting wire or strip through the resistance difference at different positions. The method for testing the room temperature resistance based on the four-wire method is adopted to detect the samples of the primary wire, the secondary wire, the composite wire or the strip or the Bi-system high-temperature superconducting composite wire or the strip in the processing process of the Bi-system high-temperature superconducting wire or the strip, and the processing uniformity in different processing stages is represented by the resistance difference at different positions, so that the real-time monitoring of the processing uniformity in the preparation process of the Bi-system high-temperature superconducting wire or the strip is realized, and a guide direction is provided for optimizing the processing parameters in the preparation process of the Bi-system high-temperature superconducting wire or the strip and improving the processing uniformity of the wire.

Description

A method for characterizing the processing uniformity of Bi-based high-temperature superconducting wires or strips

technical field

The invention belongs to the field of performance testing and characterization of high-temperature superconducting wire strips, and particularly relates to a method for characterizing the processing uniformity of Bi-series high-temperature superconducting wire rods or strips.

Background technique

The macroscopic current-carrying properties and uniformity of mechanical properties of Bi-based high-temperature superconducting wires are the key to their engineering applications. In addition, core wire leakage is a key problem that hinders the application of Bi-based high-temperature superconducting tapes to magnet technology. And good wire or strip processing uniformity can effectively reduce the core break rate, which is very important to improve the macroscopic current-carrying performance and mechanical properties uniformity of Bi-based high-temperature superconducting wire strips; at the same time, good processing uniformity can ensure silver The uniformity of matrix deformation effectively reduces the probability of core wire leakage.

The uniformity of wire or strip processing depends to a large extent on the uniformity of the deformation of the silver matrix. The cross-sectional size of silver in different positions of the same wire or strip is an important parameter to reflect the processing uniformity of the wire or strip; at the same time, adjusting the cross-sectional size of silver in the wire or strip is also an important factor to improve the processing uniformity of the wire or strip. method. Therefore, comparing the cross-sectional size of silver in different wires or strips can provide basic data support for improving the processing uniformity of wires or strips.

Currently, there are very limited methods for testing the processing uniformity of Bi-based HTS wires or strips.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a method for characterizing the processing uniformity of Bi-based high-temperature superconducting wires or strips in view of the above-mentioned deficiencies of the prior art. This method is based on the method of testing room temperature resistance by the four-wire method. The samples were tested, and the resistance difference at different positions was used to characterize the processing uniformity of different processing stages, and real-time monitoring of the processing uniformity during the preparation of Bi-based high-temperature superconducting wires or strips was realized. Processing parameters during strip preparation and improving wire processing uniformity provide guidance.

In order to solve the above-mentioned technical problems, the technical solution adopted in the present invention is: a method for characterizing the processing uniformity of Bi-based high-temperature superconducting wires or strips, characterized in that the method is based on the principle of four-wire method to test room temperature resistance for Bi-based high-temperature superconducting wires. The resistance at different positions of the superconducting wire or strip is tested, and then the processing uniformity of the Bi-based high-temperature superconducting wire or strip is characterized by the resistance difference at different positions.

The invention adopts the method of testing the room temperature resistance by the four-wire method. By obtaining the room temperature resistance of the Bi-series high-temperature superconducting wire or strip at different positions, and comparing them, the Bi-series high-temperature superconducting wire or strip is characterized by the resistance difference at different positions. The method is accurate, fast, simple to operate, safe and non-destructive.

The above-mentioned method for characterizing the processing uniformity of Bi-based high-temperature superconducting wires or strips is characterized in that the method comprises the following steps:

Step 1: The first wire, the second wire, the third wire and the fourth wire are wound and fixed on the profile in turn, and the fixed positions of the first wire, the second wire, the third wire and the fourth wire on the profile are set as: In the first position, determine the distance between the fixing point of the second wire on the profile and the fixing point of the third wire on the profile as L; the profile is a Bi-series high temperature superconducting wire or strip;

Step 2: Load the current I through the first wire and the fourth wire and form a loop with the profile, and then measure the voltage U between the second wire and the third wire. According to Ohm's law R=U/I, the first position is calculated. the resistance R ₁ of the profile of length L;

Step 3: Adjust the winding and fixing positions of the first wire, the second wire, the third wire and the fourth wire on the profile in turn, and ensure that the fixing point of the second wire on the profile and the third wire on the profile are fixed. The distance L between the fixed points remains unchanged until it is adjusted to the i-th position, where i is a natural number and i≥2. According to the loading and measurement process in step 2, calculate the length of the profile at different positions after adjustment. resistance, until the resistance R _i is obtained;

Step 4: According to the resistances R ₁ ˜R _i obtained in Step 2 and Step 3, calculate the average resistance value R _a of the profile with length L, and then calculate the resistance and average resistance of the profile with length L at each position The degree of deviation D _i of _Ra , where Di=|R _a -R _i |/R _a ×100%, and the maximum value of the degree of deviation D _i is the degree of maximum deviation D _m , and the maximum degree of deviation D _m is selected to characterize the profile Processing uniformity of source Bi-based HTS wire or strip.

In the present invention, the four-wire method is used to test the room temperature resistance of the Bi-series high-temperature superconducting wire or strip at different positions, and then the maximum deviation D _m of the resistance of the Bi-series high-temperature superconducting wire or strip is obtained to characterize the Bi-series high temperature superconducting wire or strip. The processing uniformity of high temperature superconducting wires or strips, so that by monitoring and comparing the processing uniformity of Bi-based high temperature superconducting wires or strips with the same processing parameters but different thicknesses of silver sleeves, it is necessary to adjust the processing parameters of silver superconducting wires or strips. ratio, or by monitoring and comparing the processing uniformity of Bi-based high-temperature superconducting wires or strips prepared with different processing parameters, providing guidance for adjusting processing parameters, and ultimately improving the processing of Bi-based high-temperature superconducting wires or strips. Uniformity improves the overall current-carrying performance and mechanical properties of Bi-series high-temperature superconducting wire strips, and promotes its engineering application process; in addition, the use of wire measurement is suitable for a wide range of profile lengths, simple operation, sampling spoon, convenient and flexible, The equipment requirements are not high.

The above-mentioned method for characterizing the processing uniformity of Bi-series high-temperature superconducting wires or strips, is characterized in that, the materials of the first wire, the second wire, the third wire and the fourth wire described in step 1 are all copper; The length of the profile is not less than 5cm, and the profile is a primary wire, secondary wire, composite wire or strip, or Bi-based high-temperature superconducting composite wire or strip in the process of Bi-series high-temperature superconducting wire or strip. The intercepted sample; in step 1, L≥1cm, and when 1cm≤L<10cm, the measurement accuracy of L is not less than 0.01cm, and when L≥10cm, the measurement accuracy of L is not less than 0.1cm. The wire of the preferred material has good electrical conductivity and is easy to obtain; the overall error of the profile of the preferred length in the subsequent characterization process is small, which improves the accuracy of the test results of each parameter; the method of the present invention is suitable for Bi series high temperature superconducting wire or For each process wire rod after strip processing, the process detection process is established by detecting the uniformity of each process wire rod, thereby ensuring the processing uniformity of the final product; flexibly select the measurement length according to the profile, which is convenient to obtain the processing uniformity of different profiles At the same time, the measurement accuracy is selected according to the measurement length, so as to minimize the errors introduced by the measurement and ensure the accuracy of the characterization method of the present invention.

The above-mentioned method for characterizing the processing uniformity of Bi-based high-temperature superconducting wires or strips is characterized in that, the current I described in step 2 is a changing current, then the voltage U is a changing voltage, and the UI is fitted to obtain a fitting curve, the slope of the fitted curve is the resistance R ₁ of the profile of length L at the first position. The resistance measurement methods of the present invention are various.

The above-mentioned method for characterizing the processing uniformity of Bi-based high-temperature superconducting wires or strips is characterized in that, in step 2, the current I is a variable current, and the loop formed by the first wire and the fourth wire and the profile is A voltage dividing resistor with a resistance value of r is set in series, then the voltages U ₀ and U of the series resistor are both changing voltages, and the fitting curve is obtained by fitting U-(U ₀ /r), then the slope of the fitting curve is The resistance R ₁ of the profile of length L at the 1st position. The above-mentioned preferred resistance measurement methods are various, which further improves the applicable scope of the characterization method of the present invention.

The above-mentioned method for characterizing the processing uniformity of Bi-based high-temperature superconducting wires or strips is characterized in that when the maximum deviation D _m in step 4 is greater than the preset value of the processing uniformity of Bi-based high-temperature superconducting wires or strips When it is 5%, it means that the processing uniformity of the Bi-series high-temperature superconducting wire or strip from the profile is poor. When the maximum deviation D _m is less than 5% of the preset value of the processing uniformity of the Bi-series high-temperature superconducting wire or strip, It shows that the Bi-series high-temperature superconducting wires or strips from profiles have good processing uniformity.

The above-mentioned method for characterizing the processing uniformity of Bi-based high-temperature superconducting wires or strips is characterized in that the method comprises the following steps:

Step 1. Wind and fix the profiles on the take-up reel, the first axis conductor, the second axis conductor, the third axis conductor, the fourth axis conductor and the pay-off plate in turn, and wrap the first axis conductor, the second axis conductor, the The fixed position of the triaxial conductor and the fourth axis conductor on the profile is set as the first position, and the distance between the contact tangent point of the second axis conductor on the profile and the contact tangent point of the third axis conductor on the profile is determined as L '; the profiles are Bi-series high temperature superconducting wires or strips;

Step 2: Load current I' through the first and fourth axis conductors and form a loop with the profile, and then measure the voltage U' between the second and third axis conductors. According to Ohm's law R=U/I, Calculate the resistance R ₁ ' of the profile with length L' at the first position;

Step 3: Rotate the take-up reel and the pay-out reel simultaneously in order to adjust the winding and fixing positions of the first axis conductor, the second axis conductor, the third axis conductor and the fourth axis conductor respectively on the profile, and ensure that the second axis The distance L' between the contact tangent point of the shaft conductor on the profile and the contact tangent point of the third shaft conductor on the profile remains unchanged until it is adjusted to the jth position, where j is a natural number and j≥2, according to step 2 During the loading and measurement process in , calculate the resistance of the profiles with length L' at different positions after adjustment, until the resistance R _j ' is obtained;

Step 4: According to the resistances R ₁ ′～R _j ′ obtained in Step 2 and Step 3, calculate the average resistance value R _a ′ of the profile with a length of L′, and then calculate the resistance and average resistance value _Ra at each position. ' deviation degree D _i ', in which, D _i '=|R _a '-R _j '|/R _a '×100%, and the maximum value in the deviation degree D _i ' is the maximum deviation degree D _m ', select The maximum deviation D _m ′ characterizes the processing uniformity of the Bi-based high-temperature superconducting wire or strip from the profile.

The invention adopts the four-wire method to test the room temperature resistance at different positions in the Bi series high temperature superconducting wire or strip, uses the shaft conductor to replace the wire for measurement, and fixes the position of each shaft conductor, so that the profile is retracted and placed to measure the different positions of the profile The resistance at the place is convenient for the continuous measurement of the profile, and it is suitable for the profile with a large length.

The above-mentioned method for characterizing the processing uniformity of Bi-based high temperature superconducting wires or strips is characterized in that the materials of the first axis conductor, the second axis conductor, the third axis conductor and the fourth axis conductor are all copper ; The length of the profile is not less than 50cm, and the profile is a primary wire, secondary wire, composite wire or strip, or Bi-based high-temperature superconducting composite wire or strip in the process of Bi-series high-temperature superconducting wire or strip. The intercepted sample from above; the L'≥1cm, and when 1cm≤L'<10cm, the measurement accuracy of L' is not less than 0.01cm, and when L'≥10cm, the measurement accuracy of L' is not less than 0.1cm . The shaft conductor of the preferred material has good electrical conductivity and is easy to obtain; since the shaft conductor is used for continuous measurement, the overall error of the profile of the preferred length in the subsequent characterization process is small, and the accuracy of the test results of each parameter is improved; the present invention The method is suitable for each process wire after the Bi series high temperature superconducting wire or strip is processed. By detecting the uniformity of each process wire, a process detection process is established to ensure the processing uniformity of the final product; flexible selection according to profiles Measuring the length is convenient to obtain the processing uniformity of different profiles; at the same time, the measuring accuracy is selected according to the measuring length, so as to minimize the error introduced by the measurement and ensure the accuracy of the characterization method of the present invention.

The above-mentioned method for characterizing the processing uniformity of Bi-series high-temperature superconducting wires or strips is characterized in that, in step 2, the current I' is a changing current, then the voltage U' is a changing voltage, and for U'-I' Fitting is performed to obtain a fitting curve, and the slope of the fitting curve is the resistance R ₁ ' of the profile with the length L' at the first position.

The above-mentioned method for characterizing the processing uniformity of Bi-series high-temperature superconducting wires or strips is characterized in that in step 2, the current I' is a variable current, and the first axis conductor and the fourth axis conductor are formed with the profiles. A voltage dividing resistor with a resistance value of r is set in series in the loop of , then the voltages U ₀ ' and U' of the series resistors are both changing voltages, and the fitting curve is obtained by fitting U'-(U ₀ '/r), Then the slope of the fitting curve is the resistance R ₁ ' of the profile with length L' at the first position.

The above-mentioned method for characterizing the processing uniformity of Bi-based high-temperature superconducting wires or strips is characterized in that when the maximum deviation D _m ′ in step 4 is greater than the preset processing uniformity of Bi-based high-temperature superconducting wires or strips When the value is 5%, it means that the processing uniformity of the Bi-series high-temperature superconducting wire or strip from the profile is poor. When the maximum deviation D _m ′ is less than the preset value of 5% of the processing uniformity of the Bi-series high-temperature superconducting wire or strip , indicating that the Bi-based high-temperature superconducting wire or strip from the profile has good processing uniformity.

In the present invention, the processing technology of the Bi series high temperature superconducting wire is as follows: the Bi series powder is loaded into the primary silver tube and then drawn to obtain the primary wire, and the primary wire is loaded into the secondary silver tube and assembled and then drawn to obtain the secondary wire , the secondary wire rod is assembled into the tertiary silver alloy tube and then drawn to obtain a composite wire rod. After heat treatment, a textured structure is formed to obtain a Bi series high temperature superconducting wire.

The processing technology of the Bi-based high-temperature superconducting tape in the present invention is as follows: the Bi-based powder is loaded into a primary silver tube and then drawn to obtain a primary wire, and the primary wire is loaded into a secondary silver alloy tube for assembly and then drawn to obtain a secondary wire. The secondary wire rod and the secondary wire rod are rolled by a rolling mill to obtain a composite strip, and after heat treatment, a textured structure is formed, and a Bi-based high temperature superconducting strip is obtained.

Compared with the prior art, the present invention has the following advantages:

1. The present invention is based on the method of testing room temperature resistance by the four-wire method, and is used for primary wires, secondary wires, composite wires or strips, or Bi-based high-temperature superconducting composite wires or The strip samples are tested, and the processing uniformity in different processing stages is characterized by the resistance difference at different positions, which realizes the real-time monitoring of the processing uniformity during the preparation of Bi-based high-temperature superconducting wires or strips. Processing parameters during wire rod or strip preparation, providing guidance for improving wire processing uniformity.

2. The method of the present invention is accurate, fast, simple to operate, safe and non-destructive, and the measurement method combined with the shaft conductor can realize on-line continuous monitoring of the processing uniformity of Bi-series high-temperature superconducting wires or strips, which is convenient for Bi-series high-temperature superconducting wires or strips. Uniformity evaluation of strip processing.

3. The present invention proposes an effective quantitative index for evaluating the processing uniformity of Bi-series high-temperature superconducting wires or strips, that is, the maximum deviation of wire resistance Dm, which provides a quantifiable exact index for evaluating the processing uniformity of wires or strips. It is convenient to compare and analyze the processing uniformity of different wires or strips.

4. By monitoring and comparing the processing uniformity of different Bi-series high-temperature superconducting wires or strips, the present invention provides a basis and guiding direction for optimizing the processing parameters and silver tube dimensions in the processing of Bi-series high-temperature superconducting wires or strips. It is beneficial to improve the processing uniformity of Bi-based high-temperature superconducting wires or strips, improve the overall current-carrying properties and mechanical properties of Bi-based high-temperature superconducting wires, and promote their engineering application process.

The technical solutions of the present invention will be further described in detail below through the accompanying drawings and embodiments.

Description of drawings

FIG. 1 is a schematic diagram of testing the Bi-based high temperature superconducting wires of Examples 1, 3, 4, 5, 7 and 9 of the present invention.

FIG. 2 is a schematic diagram of the test of the Bi-based high temperature superconducting wire of Example 2 of the present invention.

3 is a schematic diagram of the test of the Bi-based high temperature superconducting wire of Example 6 of the present invention.

4 is a schematic diagram of a test of the Bi-based high temperature superconducting tape of Example 8 of the present invention.

Explanation of reference numbers:

1—the first wire; 2—the second wire; 3—the third wire;

4—the fourth wire; 5—the profile; 6—the first axis conductor;

7—the second axis conductor; 8—the third axis conductor; 9—the fourth axis conductor;

10—Reel reel; 11—Reel reel.

Detailed ways

Example 1

This embodiment includes the following steps:

Step 1. Cut a sample with a length of 100cm from the head end of the primary wire (10m in length) in the Bi2212 high temperature superconducting wire processing process as a profile 5, and then connect the first wire 1, the second wire 2, the third wire 3 and the The fourth wire 4 is wound and fixed on the profile 5 in turn, and the fixed positions of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 are set as the first position (the head end of the profile 5). The distance L between the fixing point of the second wire 2 on the profile 5 and the fixing point of the third wire 3 on the profile 5 is 10.0 cm; the first wire 1, the first wire The materials of the second wire 2, the third wire 3 and the fourth wire 4 are all copper;

Step 2, load current I through the first wire 1 and the fourth wire 4 and form a loop with the profile 5, then measure the voltage U between the second wire 2 and the third wire 3, the current I is a constant increasing current, and the current I is 0~1A, the increase range is 0.1A/s, the corresponding voltage U is the changing voltage, and the fitting curve is obtained by fitting the UI. The slope of the fitting curve is 0.00211, that is, the length of the profile at the first position is 10.0cm The resistance R ₁ of 5 = 0.00211Ω; the test schematic diagram of this embodiment is shown in FIG. 1 ;

Step 3: Adjust the winding and fixing positions of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 in turn to the second position (within the range of 20cm to 40cm from the head end of the profile 5). ), the third position (within the range of 40cm-60cm from the head end of the profile 5), the fourth position (within the range of 60cm-80cm from the head end of the profile 5), and the fifth position (within the range of 80cm-100cm from the head end of the profile 5) inside), and ensure that the distance L between the fixed point of the second wire 2 on the profile 5 and the fixed point of the third wire 3 on the profile 5 is 10.0 cm unchanged. According to the loading and measurement process in step 2, respectively It is calculated that the resistance of the profile 5 with a length of 10.0cm from the second position to the fifth position after adjustment is R ₂ =0.00214Ω, R ₃ =0.00234Ω, R ₄ =0.00233Ω and R ₅ =0.00215Ω in sequence;

Step 4: According to the resistances R ₁ to R ₅ obtained in Step 2 and Step 3, calculate the average resistance value _Ra = 0.00221 of the profile 5 with a length of 10.0 cm, and then calculate the profile 5 with a length of 10.0 cm at each position. The degree of deviation D _i between the resistance and the average value of resistance _Ra , wherein, D _i =|R _a -R _i |/R _a ×100%, the maximum value of the degree of deviation D _i is obtained, that is, the maximum degree of deviation D _m =4.5 %, indicating that the processing uniformity of the primary wire rod during the processing of the Bi2212 high-temperature superconducting wire rod sourced from Profile 5 is good.

Example 2

This embodiment includes the following steps:

Step 1. Cut a sample with a length of 60cm from the head end of the secondary wire (6m in length) during the Bi2212 high temperature superconducting wire processing process as a profile 5, and then connect the first wire 1, the second wire 2, and the third wire 3. and the fourth wire 4 are wound and fixed on the profile 5 in turn, and the fixed position of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 is set as the first position (the head of the profile 5). The distance L between the fixing point of the second wire 2 on the profile 5 and the fixing point of the third wire 3 on the profile 5 is 10.0 cm; the first wire 1, The materials of the second wire 2, the third wire 3 and the fourth wire 4 are all copper;

Step 2: Add a voltage divider resistor with resistance value r=0.001Ω to the first copper wire 1, the fourth copper wire 4 and the loop with the profile 5, load the current I through the first wire 1 and the fourth wire 4 and connect with the profile. 5. Form a loop, then measure the voltage at both ends of the voltage dividing resistor as U ₀ , measure the voltage U between the second wire 2 and the third wire 3, the current I is a current that increases at a constant speed, the current I is 0-1A, and the increase range is 0.1 A/s, corresponding to the obtained voltage U is the changing voltage, fitting U-(U ₀ /r) to get the fitting curve, the slope of the fitting curve is 7.91384×10 ^-4 , that is, the length at the first position is 10.0 The resistance R ₁ of the profile 5 of cm is 7.91384×10 ^-4 Ω; the test schematic diagram of this embodiment is shown in FIG. 2 ;

Step 3: Adjust the winding and fixing positions of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 in turn to the second position (within the range of 20cm to 40cm from the head end of the profile 5). ), the third position (within the range of 40cm to 60cm from the head end of the profile 5), and ensure that the distance L between the fixing point of the second wire 2 on the profile 5 and the fixing point of the third wire 3 on the profile 5 is 10.0cm remains unchanged. According to the loading and measurement process in step 2, the resistances of the profile 5 with a length of 10.0cm at the second and third positions after adjustment are calculated as R ₂ =8.08842×10 ^-4 Ω, R 2 =8.08842×10 -4 Ω ₃ = 8.15882 × 10 ^-4 Ω;

Step 4: According to the resistances R ₁ to R ₃ obtained in Step 2 and Step 3, calculate the average resistance value _Ra = 8.05369×10 ^-4 Ω of the profile 5 with a length of 10.0 cm, and then calculate the length at each position as The degree of deviation D _i between the resistance of the 10.0 cm profile 5 and the average resistance value _Ra , wherein, D _i =|R _a -R _i |/R _a ×100%, the maximum value in the degree of deviation D _i is obtained, that is, the maximum deviation The degree of D _m =1.74%, indicating that the processing uniformity of the secondary wire rod during the processing of the Bi2212 high temperature superconducting wire rod sourced from Profile 5 is good.

The wires in this embodiment can also be replaced by corresponding shaft conductors, and the used profiles 5 can be processed secondary wires (6m in length). , the second axis conductor 7, the third axis conductor 8, the fourth axis conductor 9 and the pay-off reel 11, by rotating the take-up reel 10 and the pay-off reel 1 at the same time, adjust the first axis conductor 6, the second axis conductor respectively 7. The winding and fixing positions of the third axis conductor 8 and the fourth axis conductor 9 on the profile 5, and then carry out the corresponding resistance measurement and the processing uniformity characterization of the secondary wire.

Example 3

This embodiment includes the following steps:

Step 1. In the process of Bi2212 high-temperature superconducting wire processing, the head end and the tail end of the third wire rod (length is 14m) are respectively cut out samples with a length of 20cm as profile 5, and then the first wire 1, the second wire 2, the first wire 2, the first wire The three wires 3 and the fourth wire 4 are wound and fixed on the profile 5 in turn, and the fixed positions of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 are set as the first position (three times The length of the wire head end is 20cm), and ensure that the distance L between the fixing point of the second wire 2 on the profile 5 and the fixing point of the third wire 3 on the profile 5 is 10.0cm; the first wire 1 , the material of the second wire 2, the third wire 3 and the fourth wire 4 are all copper;

Step 2, load current I through the first wire 1 and the fourth wire 4 and form a loop with the profile 5, then measure the voltage U between the second wire 2 and the third wire 3, the current I is a constant increasing current, and the current I It is 0~1A, the increase range is 0.1A/s, the corresponding voltage U is the changing voltage, and the fitting curve is obtained by fitting UI. The slope of the fitting curve is 0.00311, that is, the length of the profile at the first position is 10.0cm. The resistance R ₁ of 5 = 0.00311Ω; the test schematic diagram of this embodiment is shown in FIG. 1 ;

Step 3: Adjust the winding and fixing positions of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 to the second position in turn (the sample with the end length of the third wire 20cm), And ensure that the distance L between the fixed point of the second wire 2 on the profile 5 and the fixed point of the third wire 3 on the profile 5 is 10.0cm unchanged, according to the loading and measurement process in step 2, respectively. Calculated and adjusted The resistance of the profile 5 with a length of 10.0 cm at the second position is R ₂ =0.00315Ω;

Step 4: According to the resistances R ₁ and R ₂ obtained in Step 2 and Step 3, calculate the average resistance value _Ra = 0.00313 of the profile 5 with a length of 10.0 cm, and then calculate the profile 5 with a length of 10.0 cm at each position. The degree of deviation D _i between the resistance and the average value of resistance _Ra , wherein, D _i =|R _a -R _i |/R _a ×100%, the maximum value of the degree of deviation D _i is obtained, that is, the maximum degree of deviation D _m =0.64 %, indicating that the processing uniformity of the tertiary wire rod during the processing of the Bi2212 high temperature superconducting wire rod from Profile 5 is good.

Example 4

This embodiment includes the following steps:

Step 1. Two Bi2212 high-temperature superconducting wires with the same processing parameters but different primary silver tube thickness and the same secondary silver tube and tertiary silver alloy tube (respectively marked as A and B, wherein the primary silver tube thickness of A is less than B The head end and the tail end of the third wire (all 50m in length) during the processing of the thickness of the primary silver tube) were cut with samples with a length of 40cm (denoted as A ₁ , A ₂ and B ₁ , B ₂ ) as profile 5, Then, the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 are wound and fixed on the A in the profile 5 in turn, and the first wire 1, the second wire 2, the third wire 3 and the fourth wire are 4. The fixed position of A on the profile 5 is set as the _first position (that is, within the range of 0-20cm from the head end of A1), and ensure that the fixed point of the second wire 2 on the profile 5 and the third wire 3 on the profile 5. The distance L between the fixed points is 10.0cm; the materials of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 are all copper;

Step 2, load current I through the first wire 1 and the fourth wire 4 and form a loop with the profile 5, then measure the voltage U between the second wire 2 and the third wire 3, the current I is a constant increasing current, and the current I is 0~1A, the increase range is 0.1A/s, the corresponding voltage U is the changing voltage, and the fitting curve is obtained by fitting UI. The slope of the fitting curve is 0.00389, that is, the length of the first position of A is 10.0cm The resistance R ₁ =0.00389Ω of the profile 5; the test schematic diagram of this embodiment is shown in Figure 1;

Step 3: Adjust the winding and fixing positions of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 in turn to the second position of A (that is, the head end of A ₁ is 20cm ~ 40cm) range), the 3rd position (that is, the head end of A ₂ is within the range of 0-20cm) and the 4th position (that is, the head end of A ₂ is within the range of 20cm-40cm), and ensure that the second wire 2 is fixed on the profile 5 The distance L between the point and the fixed point of the third wire 3 on the profile 5 is 10.0 cm unchanged. According to the loading and measurement process in step 2, the length from the second position to the fourth position after adjustment is calculated to be 10.0 cm. The resistance of the profile 5 of cm is R ₂ =0.00389Ω, R ₃ =0.00393Ω and R ₄ =0.00394Ω in sequence;

Adjust the winding and fixing positions of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 in turn to the _first position of B (that is, within the range of 0cm to 20cm at the head end of B1) , the second position (that is, within the range of 20cm to 40cm _of the head end of B1), the third position (that is, within the range of ₀ to 20cm of the head end of B2), and the fourth position (that is, within the range of 20cm to 40cm of the head end of B2 ₎ ), and ensure that the distance L between the fixed point of the second wire 2 on the profile 5 and the fixed point of the third wire 3 on the profile 5 is 10.0 cm unchanged, according to the loading and measurement process in step 2, respectively calculate The resistances of the profile 5 with a length of 10.0cm at the first position to the fourth position of B are R ₁ =0.00351Ω, R ₂ =0.00352Ω, R ₃ =0.00352Ω and R ₄ =0.00352Ω in sequence;

Step 4: According to the resistances R ₁ to R ₄ of A and B obtained in Step 2 and Step 3, the average resistance value of the profile 5 with a length of A of 10.0 cm is calculated to be R _a = 0.00391, and the length of B is a profile of 10.0 cm. The average value of resistance of 5 is _Ra = 0.00352, and then the degree of deviation D _i of the resistance of the profile 5 with a length of 10.0 cm at each position in A and B from the average value of resistance Ra is calculated, where D _{i =} |R _a - R _i |/R _a ×100%, the maximum value of the deviation degree D _i of A, that is, the maximum deviation degree D _m =0.70%, and the maximum value of the deviation degree D _i of B, that is, the maximum deviation degree D _m =0.21% , indicating that the processing uniformity of the Bi-based high-temperature superconducting wire from A source and B-source in profile 5 is better, and the processing uniformity of the Bi-based high-temperature superconducting wire from B source is better, which indicates that the primary silver tube wall thickness The increase of α is beneficial to improve the processing uniformity of Bi-based high-temperature superconducting wires.

Example 5

This embodiment includes the following steps:

Step 1. During the processing of two Bi2212 high-temperature superconducting wires with different processing parameters and similar thickness of silver tubes (respectively denoted as A and B, where A is processed by an eight-die wire drawing machine, and B is processed by a single-die wire drawing machine). Samples with a length of 40cm (denoted as A ₁ , A ₂ and B ₁ , B ₂ ) were taken from the head and tail ends of the third wire (both 50m in length) as profile 5, and then the first wire 1 and the second wire were 2. The third wire 3 and the fourth wire 4 are wound and fixed on A in the profile 5 in turn, and the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 are fixed on the A in the profile 5 at a fixed position. It is the _first position (that is, the head end of A1 is within the range of 0-20cm), and the distance L between the fixed point of the second wire 2 on the profile 5 and the fixed point of the third wire 3 on the profile 5 is determined to be 10.0 cm; the materials of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 are all copper;

Step 2, load current I through the first wire 1 and the fourth wire 4 and form a loop with the profile 5, then measure the voltage U between the second wire 2 and the third wire 3, the current I is a constant increasing current, and the current I is 0 to 1A, the increase range is 0.1A/s, the corresponding voltage U is the changing voltage, and the fitting curve is obtained by fitting UI. The slope of the fitting curve is 0.00336, that is, the length of the first position of A is 10.0cm The resistance R ₁ =0.00336Ω of the profile 5; the test schematic diagram of this embodiment is shown in Figure 1;

Step 3: Adjust the winding and fixing positions of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 in turn to the second position of A (that is, the head end of A ₁ is 20cm ~ 40cm) range), the 3rd position (that is, the head end of A ₂ is within the range of 0-20cm) and the 4th position (that is, the head end of A ₂ is within the range of 20cm-40cm), and ensure that the second wire 2 is fixed on the profile 5 The distance L between the point and the fixed point of the third wire 3 on the profile 5 is 10.0 cm unchanged. According to the loading and measurement process in step 2, the length from the second position to the fourth position after adjustment is calculated to be 10.0 cm. The resistance of the profile 5 of cm is R ₂ =0.00336Ω, R ₃ =0.00369Ω and R ₄ =0.00362Ω in sequence;

Adjust the winding and fixing positions of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 in turn to the second position of B (that is, within the range of 0cm to 20cm _of the head end of B1) , the second position (that is, within the range of 20cm to 40cm _of the head end of B1), the third position (that is, within the range of ₀ to 20cm of the head end of B2), and the fourth position (that is, within the range of 20cm to 40cm of the head end of B2 ₎ ), and ensure that the distance L between the fixed point of the second wire 2 on the profile 5 and the fixed point of the third wire 3 on the profile 5 is 10.0 cm unchanged. According to the loading and measurement process in step 2, calculate The resistances of the profile 5 with a length of 10.0cm at the first position to the fourth position of B are R ₁ =0.00351Ω, R ₂ =0.00352Ω, R ₃ =0.00352Ω and R ₄ =0.00352Ω in sequence;

Step 4: According to the resistances R ₁ to R ₄ of A and B obtained in Step 2 and Step 3, the average resistance value of the profile 5 with a length of A of 10.0 cm is calculated to be R _a = 0.00336, and the length of B is a profile of 10.0 cm. The average value of resistance of 5 is _Ra = 0.00352, and then the degree of deviation D _i of the resistance of the profile 5 with a length of 10.0 cm at each position in A and B from the average value of resistance Ra is calculated, where D _{i =} |R _a - R _i |/R _a ×100%, the maximum value of the deviation degree D _i of A, that is, the maximum deviation degree D _m =5.20%, and the maximum value of the deviation degree D _i of B, that is, the maximum deviation degree D _m =0.21% , indicating that the processing uniformity of the Bi-based high-temperature superconducting wire derived from B in profile 5 is good, indicating that the use of a single-die wire drawing machine is beneficial to improve the processing uniformity of the Bi-based high-temperature superconducting wire.

Example 6

Step 1. Take a sample with a length of 600cm from the tertiary wire (500m in length) in the Bi2212 high temperature superconducting wire processing process as the profile 5, and then the profile 5 is wound and fixed on the take-up reel 10, the first axis conductor 6, On the second axis conductor 7, the third axis conductor 8, the fourth axis conductor 9 and the pay-off reel 11, place the first axis conductor 6, the second axis conductor 7, the third axis conductor 8 and the fourth axis conductor 9 on the profile The fixed position on the The distance L' between the tangent points is 100.0 cm; the materials of the first axis conductor 6, the second axis conductor 7, the third axis conductor 8, and the fourth axis conductor 9 are all copper;

Step 2: Load current I' through the first shaft conductor 6 and the fourth shaft conductor 9 and form a loop with the profile 5, and then measure the voltage U' between the second shaft conductor 7 and the third shaft conductor 8, the current I' is The current that increases at a constant speed, the current I' is 0-1A, the increase range is 0.1A/s, the corresponding voltage U' is the changing voltage, and the fitting curve is obtained by fitting U'-I', and the slope of the fitting curve is 0.03881, that is, the resistance R ₁ ′=0.03881Ω of the profile 5 with a length of 100.0cm at the first position; the test schematic diagram of this embodiment is shown in FIG. 3 ;

Step 3: Rotate the take-up reel 10 and the pay-out reel 1 simultaneously in turn, and adjust the winding and fixing positions of the first axis conductor 6, the second axis conductor 7, the third axis conductor 8 and the fourth axis conductor 9 on the profile 5 respectively. to the second position (190.0cm～310.0cm from the end of the take-up reel), the third position (290.0cm～410.0cm from the end of the take-up reel) and the fourth position (390.0cm～510.0cm from the end of the take-up reel), and Make sure that the distance L' between the contact tangent point of the second axis conductor 7 on the profile 5 and the contact tangent point of the third axis conductor 8 on the profile 5 is 1000.0 cm unchanged. According to the loading and measurement process in step 2, The resistances of the profiles 5 with a length of 100.0 cm at positions 2 to 4 after adjustment are calculated as R ₂ ′=0.03963Ω, R ₃ ′=0.03311Ω, and R ₄ ′=0.03037Ω in sequence;

Step 4: According to the resistances R ₁ ′～R ₄ ′ obtained in Step 2 and Step 3, calculate the average resistance value R _a ′=0.03548 of the profile 5 with a length of 1000.0cm, and then calculate the resistance value of each position with a length of 1000.0cm. The degree of deviation D _i ' between the resistance of the profile 5 and the average resistance value _Ra , wherein, D _i '=|R _a '-R _j '|/R _a '×100%, the maximum value of the deviation value D _i ' is obtained That is, the maximum deviation value D _m ′=14.40%, which indicates that the processing uniformity of the Bi-based high-temperature superconducting wire from Profile 5 is poor.

Example 7

This embodiment includes the following steps:

Step 1. Take a sample with a length of 50 cm from the high-temperature superconducting wire after the high-pressure heat treatment of the Bi2212 composite wire as the profile 5, and then wrap the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 in turn. Fixed on the profile 5, the fixed position of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 is set as the first position (within the range of 0-5cm from the head end of the profile 5 ), and determine the distance L between the fixed point of the second wire 2 on the profile 5 and the fixed point of the third wire 3 on the profile 5 to be 3.00cm; the first wire 1, the second wire 2, the third wire The material of the wire 3 and the fourth wire 4 is copper;

Step 2, load current I through the first wire 1 and the fourth wire 4 and form a loop with the profile 5, then measure the voltage U between the second wire 2 and the third wire 3, the current I is a constant increasing current, and the current I is 0~1A, the increase range is 0.1A/s, the corresponding voltage U is the changing voltage, and the fitting curve is obtained by fitting the UI. The slope of the fitting curve is 0.00102, that is, the length of the profile at the first position is 3.00cm. The resistance R ₁ of 5 = 0.00102Ω; the test schematic diagram of this embodiment is shown in FIG. 4 ;

Step 3: Adjust the winding and fixing positions of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 to the second position in turn (within the range of 5cm to 10cm from the head end of the profile 5). ), the third position (within the range of 10cm to 15cm from the head end of the profile 5), the fourth position (within the range of 15cm to 20cm from the head end of the profile 5), the fifth position (within the range of 20cm to 25cm from the head end of the profile 5) inside), the 6th position (within the range of 25cm to 30cm from the head end of the profile 5), the 7th position (within the range of 30cm to 35cm from the head end of the profile 5), the 8th position (35cm to 40cm from the head end of the profile 5) range), the 9th position (within the range of 40cm-45cm from the head end of the profile 5) and the 10th position (within the range of 45cm-50cm from the head end of the profile 5), and ensure that the second wire 2 is fixed on the profile 5 The distance L between the point and the fixed point of the third wire 3 on the profile 5 is 3.00cm unchanged. According to the loading and measurement process in step 2, the length from the second position to the tenth position after adjustment is calculated to be 3.00 cm. The resistance of the profile 5 of cm is R ₂ =0.00103Ω, R ₃ =0.00108Ω, R ₄ =0.00103Ω, R ₅ =0.00103Ω, R ₆ =0.00104Ω, R ₇ =0.00106Ω, R ₈ =0.00108Ω, R ₉ =0.00104Ω and R ₁₀ =0.00104Ω;

Step 4: According to the resistances R ₁ to R ₁₀ obtained in Step 2 and Step 3, calculate the average resistance value _Ra = 0.00105 of the profile 5 with a length of 3.00 cm, and then calculate the profile 5 with a length of 3.00 cm at each position. The degree of deviation D _i between the resistance and the average value of resistance _Ra , where, D _i =|R _a -R _i |/R _a ×100%, the maximum value of the degree of deviation D _i is obtained, that is, the maximum degree of deviation D _m =3.35 %, indicating that the processing uniformity of the composite wire from Profile 5 is good.

Example 8

This embodiment includes the following steps:

Step 1. Randomly cut 6 samples with a length of 20cm on the Bi2223 high-temperature superconducting tape as profile 5, and then wrap the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 in turn and fix them on the profile. On the first sample of The distance L between the fixed point on the upper part and the fixed point of the third wire 3 on the profile 5 is 10.00cm; the materials of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 are all copper;

Step 2: Load current I through the first wire 1 and the fourth wire 4 and form a loop with the profile 5, and then measure the voltage U between the second wire 2 and the third wire 3, the current I is a constant increasing current, The current I is 0-1A, the increase range is 0.1A/s, the corresponding voltage U is the changing voltage, and the fitting curve is obtained by fitting UI. The slope of the fitting curve is 0.00216, that is, the length at the first position is 10.00cm The resistance R ₁ =0.00216Ω of the profile 5; the test schematic diagram of this embodiment is shown in Figure 1;

Step 3: Adjust the winding and fixing positions of the first wire 1, the second wire 2, the third wire 3 and the fourth wire 4 on the profile 5 to the second position (ie the second sample), the third position ( i.e. 3rd sample), 4th position (i.e. 4th sample), 5th position (i.e. 5th sample) and 6th position (i.e. 6th sample), and make sure that the second wire 2 is on the profile 5 The distance L between the fixed point of the third wire 3 and the fixed point of the third wire 3 on the profile 5 is 10.00cm unchanged. According to the loading and measurement process in step 2, the lengths from the second position to the sixth position after adjustment are calculated respectively. The resistance of the 10.00cm profile 5 is R ₂ =0.00218Ω, R ₃ =0.00216Ω, R ₄ =0.00218Ω, R ₅ =0.00218Ω and R ₆ =0.00217Ω;

Step 4: According to the resistances R ₁ to R ₆ obtained in Step 2 and Step 3, calculate the average resistance value of the profile 5 with a length of 10.00 cm R _a = 0.00217, and then calculate the profile 5 with a length of 10.00 cm at each position. The degree of deviation D _i between the resistance and the average value of resistance _Ra , where, D _i =|R _a -R _i |/R _a ×100%, the maximum value of the degree of deviation D _i is obtained, that is, the maximum degree of deviation D _m =0.54 %, indicating that the processing uniformity of the Bi2223 high-temperature superconducting tape from Profile 5 is good.

Example 9

The difference between this embodiment and Embodiment 1 is that in step 1, the distance between the fixing points of the second wire 2 and the third wire 3 on the profile 5 is 1.00 cm.

The above descriptions are only preferred embodiments of the present invention, and do not limit the present invention in any way. Any simple modifications, changes and equivalent changes made to the above embodiments according to the technical essence of the invention still fall within the protection scope of the technical solutions of the present invention.

Claims (9)

1. A method for representing the processing uniformity of a Bi-based high-temperature superconducting wire or strip is characterized in that the method tests the resistance of the Bi-based high-temperature superconducting wire or strip at different positions based on a room-temperature resistance testing principle by a four-wire method, and then represents the processing uniformity of the Bi-based high-temperature superconducting wire or strip through the resistance difference at different positions;

the method comprises the following steps:

firstly, a first lead (1), a second lead (2), a third lead (3) and a fourth lead (4) are sequentially wound and fixed on a section bar (5), the fixed positions of the first lead (1), the second lead (2), the third lead (3) and the fourth lead (4) on the section bar (5) are determined as a 1 st position, and the distance between the fixed point of the second lead (2) on the section bar (5) and the fixed point of the third lead (3) on the section bar (5) is determined as L; the section (5) is a Bi-series high-temperature superconducting wire or strip;

step two, loading current I through the first lead (1) and the fourth lead (4) and forming a loop with the section bar (5), then measuring voltage U between the second lead (2) and the third lead (3), and calculating resistance R of the section bar (5) with the length of L at the 1 st position according to ohm law R ═ U/I to obtain resistance R of the section bar (5)₁；

Step three, the winding fixing positions of the first lead (1), the second lead (2), the third lead (3) and the fourth lead (4) on the section bar (5) are adjusted integrally in sequence, the distance L between the fixing point of the second lead (2) on the section bar (5) and the fixing point of the third lead (3) on the section bar (5) is ensured to be unchanged until the position i is adjusted, wherein i is a natural number and i is not less than 2, the resistances of the section bar (5) with the length L at different positions after adjustment are respectively calculated according to the loading and measuring processes in the step two until the resistance R is obtained_i；

Step four, obtaining the resistance R according to the step two and the step three₁～R_iAnd calculating the average resistance value R of the section bar (5) with the length L_aThen, the resistance of the profile (5) of length L at each position is calculated together with the average value R of the resistance_aDegree of deviation D of_iWherein Di is ═ R_a-R_i|/R_aX 100% and degree of deviation D_iMaximum value of (1) is the maximum deviation degree D_mSelecting the maximum deviation D_mCharacterizing the processing uniformity of the Bi-based high-temperature superconducting wire or strip from the profile (5);

or the method comprises the following steps:

the method comprises the following steps of firstly, winding and fixing a section bar (5) on a take-up reel (10), a first shaft conductor (6), a second shaft conductor (7), a third shaft conductor (8), a fourth shaft conductor (9) and a pay-off reel (11) in sequence, setting the fixed positions of the first shaft conductor (6), the second shaft conductor (7), the third shaft conductor (8) and the fourth shaft conductor (9) on the section bar (5) as a position 1, and determining the distance between a contact tangent point of the second shaft conductor (7) on the section bar (5) and a contact tangent point of the third shaft conductor (8) on the section bar (5) to be L'; the section (5) is a Bi-series high-temperature superconducting wire or strip;

step two, loading current I 'through the first shaft conductor (6) and the fourth shaft conductor (9) to form a loop with the profile (5), measuring the voltage U' between the second shaft conductor (7) and the third shaft conductor (8), and calculating the resistance R 'of the profile (5) with the length L' at the 1 st position according to the ohm law R which is U/I₁′；

Step three, sequentially and simultaneously rotating a take-up reel (10) and a pay-off reel (11), integrally adjusting the winding fixing positions of the first shaft conductor (6), the second shaft conductor (7), the third shaft conductor (8) and the fourth shaft conductor (9) on the section bar (5) respectively, ensuring that the distance L 'between the contact tangent point of the second shaft conductor (7) on the section bar (5) and the contact tangent point of the third shaft conductor (8) on the section bar (5) is unchanged until the j position is adjusted, wherein j is a natural number and is not less than 2, respectively calculating the resistance of the section bar (5) with the length L' at different positions after adjustment according to the loading and measuring processes in the step two until the resistance R is obtained_j′；

Step four, obtaining the resistance R according to the step two and the step three₁′～R_j', calculating the average value R of the resistance of the profile (5) of length L_a' then calculating the resistance at each position and the average value of the resistance R_aDegree of deviation D of `_i', wherein D_i′＝|R_a′-R_j′|/R_a'. times.100%, and degree of deviation D_iThe maximum value in is the maximum deviation D_m', selecting the maximum deviation D_m' characterizing the processing uniformity of the Bi-based high-temperature superconducting wire or strip from the profile (5).

2. The method for characterizing the processing uniformity of the Bi-based high-temperature superconducting wire or strip according to claim 1, wherein in the first step, the first conducting wire (1), the second conducting wire (2), the third conducting wire (3) and the fourth conducting wire (4) are all made of copper; the length of the section (5) is not less than 5cm, and the section (5) is a sample cut from a primary wire, a secondary wire, a composite wire or strip in the processing process of the Bi-based high-temperature superconducting wire or strip, or the Bi-based high-temperature superconducting composite wire or strip; in the step one, L is more than or equal to 1cm, the measurement precision of L is not less than 0.01cm when L is more than or equal to 1cm and less than 10cm, and the measurement precision of L is not less than 0.1cm when L is more than or equal to 10 cm.

3. The method for characterizing the processing uniformity of the Bi-based high-temperature superconducting wire or strip according to claim 1, wherein in the second step, if the current I is a variable current and the voltage U is a variable voltage, the U-I is fitted to obtain a fitted curve, and the slope of the fitted curve is the resistance R of the section (5) with the length L at the 1 st position₁。

4. The method according to claim 1, wherein the current I in step two is a variable current, and a divider resistor with a resistance r is arranged in series in a loop formed by the first lead (1), the fourth lead (4) and the profile (5), so that a voltage U of the series resistor is a voltage U of the series resistor₀And U are both variable voltage, for U- (U)₀/R) is fitted to obtain a fitted curve, the slope of which is the resistance R of the section (5) of length L at the 1 st position₁。

5. The method according to claim 1, wherein the maximum deviation D in the fourth step is_mWhen the processing uniformity of the Bi-based high-temperature superconducting wire or strip is more than 5 percent of the preset value of the processing uniformity of the Bi-based high-temperature superconducting wire or strip, the processing uniformity of the Bi-based high-temperature superconducting wire or strip from the section (5) is poor, and when the maximum deviation degree D is higher than the preset value of the processing uniformity of the Bi-based high-temperature superconducting wire or strip, the maximum deviation degree D is_mIs less than BiWhen the preset value of the processing uniformity of the high-temperature superconducting wire or strip is 5%, the processing uniformity of the Bi system high-temperature superconducting wire or strip from the section (5) is good.

6. The method for characterizing the processing uniformity of the Bi-based high-temperature superconducting wire or strip according to claim 1, wherein the first axial conductor (6), the second axial conductor (7), the third axial conductor (8) and the fourth axial conductor (9) are all made of copper; the length of the section (5) is not less than 50cm, and the section (5) is a primary wire, a secondary wire, a composite wire or strip in the processing process of the Bi-system high-temperature superconducting wire or strip, or a intercepted sample on the Bi-system high-temperature superconducting composite wire or strip; the L ' is not less than 1cm, the measurement precision of the L ' is not lower than 0.01cm when the L ' is not less than 1cm and not more than 10cm, and the measurement precision of the L ' is not lower than 0.1cm when the L ' is not less than 10 cm.

7. The method for characterizing the processing uniformity of the Bi-based high-temperature superconducting wire or strip according to claim 1, wherein in the second step, if the current I ' is a variable current and the voltage U ' is a variable voltage, the U ' -I ' is fitted to obtain a fitted curve, and the slope of the fitted curve is the resistance R of the section (5) with the length L ' at the 1 st position₁′。

8. The method according to claim 1, wherein the current I' in step two is a variable current, and a divider resistor with a resistance r is arranged in series in a loop formed by the first axial conductor (6), the fourth axial conductor (9) and the profile (5), so that a voltage U of the series resistor is a voltage U of the series resistor₀Both ' and U ' are of varying voltage, for U ' - (U)₀'/R) is fitted to obtain a fitted curve, the slope of which is the resistance R of the profile (5) of length L' at position 1₁′。

9. The method according to claim 1, wherein the step four is performedMean maximum deviation D_mWhen the value is more than 5 percent of the preset value of the processing uniformity of the Bi-based high-temperature superconducting wire or strip, the processing uniformity of the Bi-based high-temperature superconducting wire or strip from the section (5) is poor, and when the maximum deviation D is reached_mWhen the processing uniformity of the Bi-based high-temperature superconducting wire or strip is less than 5% of the preset value of the processing uniformity of the Bi-based high-temperature superconducting wire or strip, the processing uniformity of the Bi-based high-temperature superconducting wire or strip from the profile (5) is good.

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