Superconducting strip sorting and post-processing method based on binding force between thin film layers

Abstract

The invention provides a superconducting strip sorting and post-processing method based on thin film interlayer binding force. The method comprises the steps that S1, a plurality of strips to be sorted are prepared into a plurality of sheet-shaped samples of the same size; s2, respectively measuring the thicknesses of the plurality of sheet-shaped samples; s3, respectively soaking the sheet-shaped samples in the corrosive liquid, and respectively recording the dissolution time of the sheet-shaped samples; s4, respectively calculating the corrosion time of the unit film layer thickness of the plurality of sheet-shaped samples; and S5, the multiple strips to be sorted are classified according to the corrosion time of the unit film layer thickness of the multiple sheet-shaped samples, and sorting is completed. According to the method, the interlayer quality of the samples is judged and sorted by comparing the difference of the corrosion speeds of different to-be-detected samples under the same condition. Compared with a conventional detection method at the present stage, the method has the remarkable advantages of being high in detection efficiency, accurate in detection result, easy and convenient to operate, wide in application range, low in cost and the like, and a new thought is provided for the superconducting strip sorting process.

Description

Technical Field

[0001] The invention relates to the field of superconducting materials, and in particular to a superconducting tape separation and post-processing method based on the bonding force between thin film layers. Background Art

[0002] High-temperature superconducting materials can operate in the liquid nitrogen temperature range (77K), have higher current carrying capacity, and can provide a stable magnetic field with higher field strength, so they have broader prospects for commercial application. Among them, the second-generation high-temperature superconducting material REBCO is prepared using biaxial texturing and thin-film epitaxial growth technology. It has good mechanical properties, higher irreversible field (irreversible field reaches 7T at 77K) and stronger current carrying capacity. At the same time, compared with the first-generation high-temperature superconducting metal silver, it uses less and has greater cost reduction space. As a result, the second-generation high-temperature superconducting material REBCO has become the high-temperature superconducting material with the most industrial application prospects recognized by the industry.

[0003] The zero resistance characteristic of superconducting materials effectively reduces the power loss caused by long-distance power transmission and realizes long-distance high-current transmission; secondly, the use of REBCO superconducting tapes in superconducting magnets can provide higher current density without losing Joule heat, thereby generating a stable magnetic field with higher magnetic field strength. At present, REBCO high-temperature superconducting tapes have been used in superconducting cables and superconducting induction heating equipment due to their significant energy-saving and efficiency-reducing advantages. The development and research in downstream fields such as photovoltaic single crystal silicon growth furnaces and controlled nuclear fusion are also becoming increasingly hot. Among them, the demand for REBCO high-temperature superconducting tapes for a single controlled nuclear fusion reactor with a power level of 100 megawatts is expected to range from tens of thousands of kilometers. Therefore, the accelerated development of fusion commercialization will effectively drive the large-scale production and cost reduction of high-temperature superconducting tapes.

[0004] With the continuous development of high-temperature superconducting application technology, the market has higher and higher performance requirements for REBCO superconducting tapes. At present, for the film layer of superconducting tapes, the interlayer bonding force of the film is one of the main factors that directly affect the quality of the tape. The quality of the superconducting tape film directly determines the current carrying capacity and excitation performance of the superconducting tape. Especially when manufacturers need to cope with the challenge of large-scale industrialization of high-performance REBCO superconducting tapes, high-performance REBCO superconducting tapes need to improve the critical current under 77K self-field while also improving the current performance of the tape under low-temperature magnetic field, which requires even higher interlayer bonding force for the tape.

[0005] In the actual production process, due to the limitations of the current processing technology, it is necessary to conduct quality inspection and sorting of the finished strips so that products with different interlayer bonding strengths can be suitable for different operating scenarios. At present, effective methods for determining the quality of superconducting film layers include the hundred-grid method, scratch method, indentation method, stretching method and bending test. Among them, the test force of the hundred-grid method and bending test is not easy to control during the test process, so the consistency of the test cannot be guaranteed, and the result judgment has a certain degree of subjectivity; the test equipment used in the scratch method, indentation method, and stretching method is relatively expensive, and the process is complicated. Therefore, the above methods are not suitable for large-scale industrial superconducting film layer bonding test sorting. Based on this, how to develop a method that can efficiently and easily sort superconducting tapes has become an urgent problem to be solved in the industry. Summary of the invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the problems of low superconducting tape sorting efficiency and quality in the prior art, and to provide a superconducting tape sorting and post-processing method based on the bonding force between thin film layers.

[0007] In order to solve the above technical problems, the present invention provides a superconducting tape sorting method based on the interlayer bonding force of thin films, which performs quality sorting of the tape by detecting the interlayer bonding force of the tape film, and comprises the following steps: step S1, preparing a plurality of tapes to be sorted into a plurality of sheet samples of the same size, wherein at least one sheet sample is prepared from any of the tapes to be sorted; step S2, measuring the thickness of the plurality of sheet samples, d1, d2, ..., d n Step S3, immerse the sheet samples in the corrosive solution respectively until the sheet samples are completely dissolved, and record the dissolution time t1, t2…t of the sheet samples respectively. n ; Step S4, respectively calculate the unit film thickness corrosion time λ1, λ2…λ of multiple sheet samples n , wherein λ=t / d; Step S5, classifying the plurality of strips to be sorted by the corrosion time per unit film thickness of the plurality of sheet samples to complete the sorting.

[0008] In one embodiment of the present invention, in step S1, a plurality of detection points are selected from different positions of any strip to be sorted, and samples are cut with the detection points as the center to form a parallel test.

[0009] In one embodiment of the present invention, in step S2: after uniformly marking samples from the same strip to be sorted, the thicknesses of multiple sheet samples are measured respectively.

[0010] In one embodiment of the present invention, in step S3, a plurality of etching tanks are used to contain etching liquid to dissolve the sheet samples, wherein any etching tank contains a plurality of the sheet samples, and the sheet samples in the same etching tank come from different strips to be sorted.

[0011] In one embodiment of the present invention, in step S3, the corrosive solution is an acidic solution, and the concentration of the acidic solution is 0.2% to 2.0%.

[0012] In one embodiment of the present invention, in step S5: the average corrosion time of the sheet samples from the same strip to be sorted is calculated by the unit film thickness corrosion time of the sheet samples to obtain the average corrosion time of multiple strips to be sorted, and the multiple strips to be sorted are classified by comparing the average corrosion time of the multiple strips to be sorted.

[0013] In one embodiment of the present invention, in step S5, the average corrosion time of the plurality of strips to be sorted is plotted into a curve to classify and sort the plurality of strips to be sorted.

[0014] In one embodiment of the present invention, in step S3, the surface of the sheet sample is cleaned by blowing, and then the cleaned sheet sample is immersed in a corrosive liquid at a standard atmospheric pressure and a constant temperature, and the corrosive liquid is maintained in a natural static state.

[0015] In one embodiment of the present invention, in step S3, the dissolution time of the sheet sample is accelerated by increasing the temperature of the etching solution.

[0016] The present invention also provides a superconducting tape post-processing method based on the bonding force between thin film layers, which includes the above-mentioned superconducting tape sorting method based on the bonding force between thin film layers and transfer processing.

[0017] The above technical solution of the present invention has the following advantages compared with the prior art: The superconducting tape sorting and post-processing method based on the interlayer bonding force of the thin film described in the present invention realizes the judgment and sorting of the interlayer quality of the samples by comparing the difference in the corrosion rate of different samples to be detected under the same conditions. When the interlayer bonding force of the sample is low, the corrosive liquid will enter the interior of the sample to be detected through the interlayer gap, thereby accelerating the corrosion rate of the sample. When the interlayer bonding force of the sample is high, the speed at which it is completely corroded will be significantly reduced, thereby enabling accurate sorting of different samples. Compared with conventional detection methods at this stage, this application has significant advantages such as high detection efficiency, accurate detection results, simple operation, wide practical range and low cost, and provides a new idea for the superconducting tape sorting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0019] Figure 1 is a flow chart of a superconducting tape sorting and post-processing method based on the bonding force between thin film layers in a preferred embodiment of the present invention; Figure 2 yes Figure 1 The figure shows a comparison of the average corrosion time of multiple strips to be sorted in the superconducting strip sorting and post-processing method based on the bonding force between thin film layers. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Embodiment 1

[0021] This embodiment provides a superconducting tape sorting method based on the interlayer bonding force of thin films, which performs quality sorting of the tape by detecting the interlayer bonding force of the tape film. It is worth noting that the interlayer bonding force of superconducting tapes is a key factor affecting their overall quality at this stage. Superconducting tapes with high quality have tightly connected interlayer films, while superconducting tapes with poor quality have connection gaps between interlayer films. Therefore, this application can use this characteristic to sort superconducting tapes by quality. The superconducting tape sorting method based on the interlayer bonding force of thin films described in the present invention realizes the judgment and sorting of the interlayer quality of samples by comparing the difference in corrosion rates of different samples to be detected under the same conditions. When the interlayer bonding force of the sample is low, the corrosive liquid will enter the interior of the sample to be detected through the interlayer gap, thereby accelerating the corrosion rate of the sample. When the interlayer bonding force of the sample is high, the speed at which it is completely corroded will be significantly reduced, thereby enabling accurate sorting of different samples. Compared with the current conventional detection methods, this application has significant advantages such as high detection efficiency, accurate detection results, simple operation, wide practical range and low cost, providing new ideas for the superconducting tape sorting process.

[0022] See also Figure 1 As shown, the superconducting tape separation method based on the bonding force between thin film layers described in this embodiment includes the following steps: Step S1, prepare multiple strips to be sorted into multiple sheet samples of the same size, wherein at least one sheet sample is prepared from any strip to be sorted; specifically, in step S1, multiple detection points are selected from different positions of any strip to be sorted, and samples are cut with the detection points as the center to form a parallel test. In this embodiment, six strips to be sorted are selected, namely 1#, 2#, 3#, 4#, 5# and 6#, and three detection points are selected for each strip to be sorted to form 18 sheet samples. Furthermore, in this application, all the above samples are divided into three groups, A, B, and C, for testing, and each group contains samples of all the strips to be sorted, thereby performing parallel tests to further reduce errors.

[0023] Step S2: measuring the thickness of a plurality of sheet samples, d1, d2, ..., d n ;Specifically, in step S2: after uniformly marking the samples from the same strip to be sorted, the thicknesses of multiple sheet samples are measured separately, thereby avoiding sample confusion and improving the accuracy of the experiment.

[0024] Step S3, immersing the sheet samples in the corrosive solution respectively until the sheet samples are completely dissolved, and recording the dissolution time t1, t2, ..., t n ; Further, in step S3, multiple etching tanks are used to hold etching liquid to dissolve the sheet sample, wherein multiple sheet samples are held in any etching tank, and the sheet samples in the same etching tank come from different strips to be sorted. Further, the substrate of the superconducting tape is metal or polymer, which is not resistant to acidic solution, so the etching liquid in this application is preferably an acidic solution, and further, in this embodiment, it is preferably a nitric acid solution, and its solution concentration is 0.2%.

[0025] Specifically, before immersing the sample, the surface of the sheet sample needs to be purged and cleaned to avoid interference from impurities, and then the cleaned sheet sample is immersed in the etching solution at the same time under standard atmospheric pressure and constant temperature, and the etching solution is maintained in a natural static state to avoid test errors caused by uneven stirring. Based on this, the samples in the same etching tank in the present application can be processed simultaneously in a stable and identical environment, thereby improving the accuracy of the detection process. In other embodiments, for thicker samples, the dissolution time of the sheet sample can be accelerated by increasing the temperature of the etching solution.

[0026] Step S4, respectively calculating the unit film thickness corrosion time λ1, λ2, ...λ of a plurality of sheet samples n , where λ=t / d; Step S5, classify the multiple strips to be sorted by the corrosion time per unit film thickness of the multiple sheet samples to complete the sorting. In this embodiment, the average corrosion time of the sheet samples from the same strip to be sorted is calculated by the corrosion time per unit film thickness of the sheet samples to obtain the average corrosion time of the multiple strips to be sorted, and the multiple strips to be sorted are classified by comparing the average corrosion time of the multiple strips to be sorted, and then the average corrosion time of the multiple strips to be sorted is plotted into a curve to classify and sort the multiple strips to be sorted. For details, see Figure 2 As shown. Figure 2 It can be clearly seen that there is no significant deviation in the test results of the three parallel tests A, B, and C. Among them, the 6# sample requires the longest corrosion time, so its interlayer bonding strength is the best. On the contrary, the 1# sample requires the shortest corrosion time, so its interlayer bonding strength is the lowest. The sorting process is completed after classification based on the above results. Embodiment 2

[0027] This embodiment provides another superconducting tape separation method based on the bonding force between thin film layers, comprising the following steps: Step S1, preparing a plurality of strips to be sorted into a plurality of sheet samples of the same size, wherein at least one sheet sample is prepared from any strip to be sorted; specifically, in step S1, selecting a plurality of detection points from different positions of any strip to be sorted, and cutting samples with the detection points as the center to form a parallel test.

[0028] Step S2: measuring the thickness of a plurality of sheet samples, d1, d2, ..., d n ;Specifically, in step S2: after uniformly marking the samples from the same strip to be sorted, the thicknesses of multiple sheet samples are measured separately, thereby avoiding sample confusion and improving the accuracy of the experiment.

[0029] Step S3, immersing the sheet samples in the corrosive solution respectively until the sheet samples are completely dissolved, and recording the dissolution time t1, t2, ..., t n ;Further, in order to increase the processing speed, the present embodiment adopts a nitric acid solution with a concentration of 2.0% for processing. In other embodiments, the corrosion can also be adaptively adjusted according to the actual material of the strip to be sorted, and the present invention does not impose specific limitations on this.

[0030] Specifically, before immersing the sample, the surface of the sheet sample needs to be purged and cleaned to avoid interference from impurities. Then, the cleaned sheet sample is immersed in the etching solution at standard atmospheric pressure and constant temperature, and the etching solution is maintained in a natural static state to avoid test errors caused by uneven stirring.

[0031] Step S4, respectively calculating the unit film thickness corrosion time λ1, λ2, ...λ of a plurality of sheet samples n , where λ=t / d; Step S5, classifying the plurality of strips to be sorted according to the unit film thickness corrosion time of the plurality of sheet samples to complete the sorting. Embodiment 3

[0032] This embodiment provides a superconducting tape post-processing method based on the bonding force between thin film layers, which includes the superconducting tape sorting method based on the bonding force between thin film layers and the transfer processing described in the first embodiment.

[0033] In summary, the superconducting tape sorting and post-processing method based on the interlayer bonding force of the thin film described in the present invention realizes the judgment and sorting of the interlayer quality of the samples by comparing the difference in the corrosion rate of different samples to be detected under the same conditions. When the interlayer bonding force of the sample is low, the corrosive liquid will enter the interior of the sample to be detected through the interlayer gap, thereby accelerating the corrosion rate of the sample. When the interlayer bonding force of the sample is high, the speed at which it is completely corroded will be significantly reduced, thereby enabling accurate sorting of different samples. Compared with conventional detection methods at this stage, this application has significant advantages such as high detection efficiency, accurate detection results, simple operation, wide practical range and low cost, and provides a new idea for the superconducting tape sorting process.

[0034] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A superconducting tape separation method based on the bonding force between thin film layers, characterized in that: The quality of the tape is sorted by detecting the interlayer bonding force of the tape film, which includes the following steps: Step S1, preparing a plurality of strips to be sorted into a plurality of sheet samples of the same size, wherein at least one sheet sample is prepared from any of the strips to be sorted; Step S2: measuring the thickness of a plurality of sheet samples, d1, d2, ..., d n ; Step S3, immersing the sheet samples in the corrosive solution respectively until the sheet samples are completely dissolved, and recording the dissolution time t1, t2, ..., t n ; Step S4, respectively calculating the unit film thickness corrosion time λ1, λ2, ...λ of a plurality of sheet samples n , where λ=t / d; Step S5, classifying the plurality of strips to be sorted according to the unit film thickness corrosion time of the plurality of sheet samples to complete the sorting.

2. The superconducting tape separation method based on the interlayer bonding force of thin films according to claim 1, characterized in that: In step S1, a plurality of detection points are selected from different positions of any strip to be sorted, and samples are cut with the detection points as the center to form a parallel test.

3. The superconducting tape separation method based on the interlayer bonding force of thin films according to claim 1, characterized in that: In step S2: after uniformly marking the samples from the same strip to be sorted, the thicknesses of the plurality of sheet samples are measured respectively.

4. The superconducting tape separation method based on the bonding force between thin film layers according to claim 1, characterized in that: In step S3, the corrosive liquid is contained in a plurality of corrosion tanks to dissolve the sheet samples, wherein any corrosion tank contains a plurality of the sheet samples, and the sheet samples in the same corrosion tank come from different strips to be sorted.

5. The superconducting tape separation method based on the bonding force between thin film layers according to claim 1, characterized in that: In step S3, the etching solution is an acidic solution, and the concentration of the acidic solution is 0.2% to 2.0%.

6. The superconducting tape separation method based on the bonding force between thin film layers according to claim 1, characterized in that: In step S5: the average corrosion time of the sheet samples from the same strip to be sorted is calculated by the unit film thickness corrosion time of the sheet samples to obtain the average corrosion time of multiple strips to be sorted, and the multiple strips to be sorted are classified by comparing their average corrosion times.

7. The superconducting tape separation method based on the bonding force between thin film layers according to claim 6, characterized in that: In step S5, the average corrosion time of the plurality of strips to be sorted is plotted into a curve so as to classify and sort the plurality of strips to be sorted.

8. The superconducting tape separation method based on the bonding force between thin film layers according to claim 1, characterized in that: In step S3, the surface of the sheet sample is cleaned by purging, and then the cleaned sheet sample is immersed in a corrosion liquid at a standard atmospheric pressure and a constant temperature, and the corrosion liquid is maintained in a natural static state.

9. The superconducting tape separation method based on the bonding force between thin film layers according to claim 1, characterized in that: In step S3, the dissolution time of the sheet sample is accelerated by increasing the temperature of the etching solution.

10. A superconducting tape post-processing method based on the bonding force between thin film layers, characterized in that: The invention comprises a superconducting tape separation method and transfer processing based on the bonding force between thin film layers as described in any one of claims 1 to 9.

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