A processing method for controlling the copper ratio of superconducting wire

Abstract

The present invention discloses a method for controlling the copper ratio in the processing of superconducting wire materials, which relates to the technical field of superconducting wire material processing and includes the following steps: obtaining the superconducting wire materials to be processed; performing an on-line copper ratio test to obtain the copper ratio change trend and the copper ratio fluctuation range; performing centerless lathe peeling according to the copper ratio change trend to obtain the superconducting wire materials to be processed with size fluctuations; finishing the superconducting wire materials to be processed with size fluctuations to a unified size by using a mold; repeating the on-line copper ratio test, centerless lathe peeling and mold finishing until the copper ratio fluctuation range meets the copper ratio fluctuation requirements to obtain superconducting wire materials with a first fluctuation range; processing the superconducting wire materials with the first fluctuation range to the designed copper ratio to obtain the final superconducting wire materials. By combining the on-line copper ratio test with centerless lathe peeling, the present application reduces the copper ratio fluctuation of the superconducting wire materials, improves the copper ratio uniformity and performance stability; and can make full use of the copper ratio non-uniform area at the head and tail of the wire materials to improve the wire material yield.

Description

Technical Field

[0001] This application relates to the technical field of superconducting wire processing, and particularly to a method for controlling the copper ratio in the processing of superconducting wires. Background Art

[0002] NbTi / Cu superconducting wire is an important component in MRI magnets. The copper ratio is an important parameter of NbTi / Cu superconducting wire, and the uniformity of the copper ratio directly determines the low-temperature performance of the superconducting wire. Therefore, it is necessary to study the method for controlling the copper ratio in the processing of superconducting wires.

[0003] The conventional processing flow of superconducting wires includes assembly, extrusion, and drawing. Among them, extrusion is an important means to achieve the effective combination and diameter reduction of supercomposites. During the extrusion process, due to its own processing characteristics, the flow of copper is not completely uniform, especially the materials at the head and tail of the ingot. The actual copper ratio has a large gap with the designed value. The copper ratio fluctuation range of conventional superconducting wires is generally ±10% of the set value. In order to ensure that the product performance meets the requirements, a large performance margin is required in the design process, and the head and tail regions of the wire need to be removed, resulting in a low yield.

[0004] In the prior art, Chinese Patent CN104123997A discloses a method for processing small copper ratio NbTi / Cu superconducting wires, including the following steps: stretching the NbTi / Cu single-core rod into a NbTi / Cu single-core hexagonal rod, cutting and straightening; processing the copper cladding and pickling; arranging the NbTi / Cu single-core hexagonal rods in the copper cladding, filling the gaps with copper plug rods, and obtaining a NbTi / Cu composite cladding by vacuum electron beam welding and capping; extruding, repeatedly stretching, multi-pass peeling, and multiple aging heat treatments on the composite cladding.

[0005] However, the above prior art does not consider the copper ratio fluctuation of superconducting wires, and the copper ratio uniformity and performance stability are poor; in addition, the above prior art does not consider the utilization of the copper ratio non-uniform regions at the head and tail, resulting in a low yield of the wire. Summary of the Invention

[0006] This application provides a method for controlling the copper ratio in the processing of superconducting wires to solve the problems that the prior art does not consider the copper ratio fluctuation of superconducting wires, the copper ratio uniformity and performance stability are poor, does not consider the utilization of the copper ratio non-uniform regions at the head and tail, and the wire yield is low.

[0007] On the one hand, this application provides a method for controlling the copper ratio in the processing of superconducting wires, including the following steps:

[0008] Step 1: Obtain the superconducting wire to be processed.

[0009] Step 2: Perform on-line copper ratio testing on the superconducting wire to be processed to obtain the copper ratio change trend and the copper ratio fluctuation range.

[0010] Step 3: Skin the superconducting wire to be processed on a centerless lathe according to the copper ratio change trend, and obtain the superconducting wire to be processed with size fluctuations.

[0011] Step 4: Finish the superconducting wire to be processed with size fluctuations to a uniform size using a die.

[0012] Step 5: Repeat Step 2 to Step 4 until the copper ratio fluctuation range of the superconducting wire to be processed meets the copper ratio fluctuation requirement, and obtain the superconducting wire with the first fluctuation range.

[0013] Step 6: Process the superconducting wire with the first fluctuation range to the designed copper ratio to obtain the final superconducting wire.

[0014] In a possible implementation, Step 1 includes: extruding, stretching, skinning, and stretching the superconducting composite ingot to obtain the superconducting wire to be processed.

[0015] In a possible implementation, in Step 2, the on-line copper ratio test uses an on-line copper ratio test device to obtain the copper ratio change trend along the axial direction of the superconducting wire to be processed, and the minimum copper ratio to the maximum copper ratio in the copper ratio change trend is the copper ratio fluctuation range.

[0016] In a possible implementation, in Step 3, the skinning on the centerless lathe uses a centerless lathe skinning device, and the skinning blade of the centerless lathe skinning device is equipped with a telescopic device for automatically adjusting the skinning amount according to the copper ratio change trend.

[0017] In a possible implementation, in Step 4, the specification of the die is smaller than the minimum size of the superconducting wire to be processed with size fluctuations in Step 3.

[0018] In a possible implementation, Step 6 includes: performing fixed-length skinning on the superconducting wire with the first fluctuation range to the designed copper ratio to obtain the final superconducting wire.

[0019] In a possible implementation, after performing fixed-length skinning on the superconducting wire with the first fluctuation range to the designed copper ratio, perform stretching, twisting, and stretching to the designed size.

[0020] A copper ratio control processing method for a superconducting wire in this application has the following advantages:

[0021] By combining the on-line copper ratio test with skinning on a centerless lathe, the copper ratio fluctuation of the superconducting wire is reduced, the copper ratio uniformity and performance stability are improved; and the non-uniform copper ratio area at the head and tail of the wire can be fully utilized to improve the wire product yield. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a schematic flow chart of a method for controlling the copper ratio during the processing of a superconducting wire provided by an embodiment of the present application. Specific embodiments

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0025] As Figure 1 shown, an embodiment of the present application provides a method for controlling the copper ratio during the processing of a superconducting wire, including the following steps:

[0026] Step 1: Obtain the superconducting wire to be processed.

[0027] Step 2: Conduct an on-line copper ratio test on the superconducting wire to be processed to obtain the copper ratio change trend and the copper ratio fluctuation range.

[0028] Step 3: According to the copper ratio change trend, perform centerless lathe peeling on the superconducting wire to be processed to obtain a superconducting wire to be processed with size fluctuations.

[0029] Step 4: Finish the superconducting wire to be processed with size fluctuations to a unified size using a mold.

[0030] Step 5: Repeat Steps 2 to 4 until the copper ratio fluctuation range of the superconducting wire to be processed meets the copper ratio fluctuation requirements, obtaining a superconducting wire with a first fluctuation range.

[0031] Step 6: Process the superconducting wire with the first fluctuation range to the designed copper ratio to obtain the final superconducting wire.

[0032] Exemplarily, Step 1 includes: extruding, stretching, peeling, and stretching a superconducting composite ingot to obtain a superconducting wire to be processed.

[0033] Specifically, the peeling in Step 1 is to remove the oxide skin on the surface of the superconducting composite ingot.

[0034] Exemplarily, in step two, the on-line copper ratio test is carried out by an on-line copper ratio test device, which is used to obtain the copper ratio change trend along the axial direction of the superconducting wire to be processed. The copper ratio fluctuation range is from the minimum copper ratio to the maximum copper ratio in the copper ratio change trend.

[0035] Exemplarily, in step three, the skiving of the centerless lathe is carried out by a centerless lathe skiving device. The skiving blade of the centerless lathe skiving device is equipped with a telescopic device, which is used to automatically adjust the skiving amount according to the copper ratio change trend.

[0036] Specifically, in step three, the skiving speed of the centerless lathe can be adjusted within the range of 2 - 15 m / min according to the actual situation to ensure that the skiving area is repeated and continuous.

[0037] Exemplarily, in step four, the specification of the die is smaller than the minimum size of the superconducting wire to be processed with size fluctuations in step three.

[0038] Exemplarily, step six includes: sizing and skiving the superconducting wire with the first fluctuation range to the designed copper ratio to obtain the final superconducting wire.

[0039] Exemplarily, after sizing and skiving the superconducting wire with the first fluctuation range to the designed copper ratio, stretching, twisting, and stretching to the designed size are carried out.

[0040] Example 1:

[0041] This example provides an implementation process for obtaining a wire with a finished product designed copper ratio of 1.500 ± 0.050:

[0042] In step one, a NbTi / Cu superconducting composite ingot with a diameter of 300 mm is extruded, stretched, skived, and stretched to obtain a superconducting wire to be processed with a diameter of 3.000 mm.

[0043] In step two, an on-line copper ratio test device is used to carry out an on-line copper ratio test on the superconducting wire to be processed in step one, to obtain the copper ratio change trend and copper ratio fluctuation range along the axial direction of the superconducting wire to be processed. The copper ratio fluctuation range is 2.200 - 4.300.

[0044] In step three, a centerless lathe skiving device is used to carry out centerless lathe skiving on the superconducting wire to be processed in step two according to the copper ratio change trend, to obtain a superconducting wire to be processed with a size fluctuation of a diameter of 2.330 - 3.000 mm.

[0045] In step four, a die with a specification of 2.19 mm is used to finish the superconducting wire to be processed with size fluctuations in step three to a diameter of 2.19 mm. The dimensional accuracy after finishing is within the range of ±0.002 mm. The copper ratio fluctuation range at this time is 2.100 - 2.300.

[0046] Step 5: Repeat Step 2 to Step 4 (during the repetition of Step 4, new-sized dies will be selected according to new size fluctuations) until the copper ratio fluctuation range of the superconducting wire to be processed meets the copper ratio fluctuation requirement (in this embodiment, the deviation of the copper ratio fluctuation is required to be within ±0.050). The diameter of the superconducting wire with the first fluctuation range obtained is 2.011 mm, and the copper ratio fluctuation range is 1.685 - 1.715.

[0047] Step 6: Cut and peel the superconducting wire with the first fluctuation range obtained in Step 5 to a diameter of 1.936 mm. At this time, the copper ratio fluctuation range is 1.450 - 1.550. Subsequently, perform stretching, twisting, and stretching to the designed size. The diameter of the final superconducting wire obtained is 0.542 mm, the copper ratio fluctuation range is 1.450 - 1.550, and the product yield is 85% (the product yield of conventional superconducting composite ingots processed to this copper ratio fluctuation range is 80%).

[0048] Example 2:

[0049] This embodiment provides an implementation process for obtaining a wire with a finished product design copper ratio of 4.600 ± 0.050:

[0050] Step 1: Extrude, stretch, cut and peel, and stretch a NbTi / Cu superconducting composite ingot with a diameter of 300 mm to obtain a superconducting wire to be processed with a diameter of 7.000 mm.

[0051] Step 2: Use an on-line copper ratio test device to perform on-line copper ratio testing on the superconducting wire to be processed in Step 1 to obtain the copper ratio change trend and copper ratio fluctuation range along the axial direction of the superconducting wire to be processed. The copper ratio fluctuation range is 5.300 - 9.800.

[0052] Step 3: Use a centerless lathe peeling device to perform centerless lathe peeling on the superconducting wire to be processed in Step 2 according to the copper ratio change trend to obtain a superconducting wire to be processed with a size fluctuation of 5.217 - 6.831 mm in diameter.

[0053] Step 4: Use a die with a specification of 5.150 mm to finish the superconducting wire to be processed with size fluctuations in Step 3 to a diameter of 5.150 mm. The dimensional accuracy after finishing is within the range of ±0.002 mm. At this time, the copper ratio fluctuation range is 4.870 - 5.120.

[0054] Step 5: Repeat Step 2 to Step 4 (during the repetition of Step 4, new-sized dies will be selected according to new size fluctuations) until the copper ratio fluctuation range of the superconducting wire to be processed meets the copper ratio fluctuation requirement (in this embodiment, the deviation of the copper ratio fluctuation is required to be within ±0.050). The diameter of the superconducting wire with the first fluctuation range obtained is 3.500 mm, and the copper ratio fluctuation range is 4.750 - 4.830.

[0055] Step 6: Cut the first superconducting wire with a fluctuation range obtained in Step 5 to a fixed length and strip its skin until the diameter reaches 3.442 mm. At this time, the copper ratio fluctuation range is 4.550 - 4.650. Then, perform stretching, twisting, and stretching to the designed size to obtain the final superconducting wire with a diameter of 1.200 mm, a copper ratio fluctuation range of 4.550 - 4.650, and a finished product rate of 82% (the finished product rate of conventional superconducting composite ingots processed to this copper ratio fluctuation range is 77.5%).

[0056] In the embodiment of the present application, by combining on-line copper ratio testing with centerless lathe skin stripping, the copper ratio fluctuation of the superconducting wire is reduced, the copper ratio uniformity and performance stability are improved; and the copper ratio non-uniform area at the head and tail of the wire can be fully utilized to improve the finished product rate of the wire.

[0057] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0058] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A method for controlling the copper ratio in the processing of superconducting wire materials, characterized in that, It includes the following steps: Step 1: Obtain the superconducting wire to be processed; Step 2: Conduct an on-line copper ratio test on the superconducting wire to be processed to obtain the copper ratio change trend and the copper ratio fluctuation range; Step 3: According to the copper ratio change trend, conduct centerless lathe peeling on the superconducting wire to be processed to obtain a superconducting wire to be processed with dimensional fluctuations; Step 4: Finish the superconducting wire to be processed with dimensional fluctuations to a uniform size using a die; Step 5: Repeat Steps 2 to 4 until the copper ratio fluctuation range of the superconducting wire to be processed meets the copper ratio fluctuation requirement to obtain a superconducting wire with the first fluctuation range; Step 6: Process the superconducting wire with the first fluctuation range to the designed copper ratio to obtain the final superconducting wire; In Step 2, the on-line copper ratio test uses an on-line copper ratio test device to obtain the copper ratio change trend along the axial direction of the superconducting wire to be processed, and the copper ratio fluctuation range is from the minimum copper ratio to the maximum copper ratio in the copper ratio change trend; Step 6 includes: Conducting fixed-length peeling on the superconducting wire with the first fluctuation range to the designed copper ratio to obtain the final superconducting wire.

2. The copper ratio control processing method of a superconducting wire according to claim 1, characterized in that, Step 1 includes: Extruding, stretching, peeling, and stretching a superconducting composite ingot to obtain the superconducting wire to be processed.

3. A method for controlling the copper ratio in the processing of superconducting wires according to claim 1, characterized in that, In Step 3, the centerless lathe peeling uses a centerless lathe peeling device, and the peeling blade of the centerless lathe peeling device is equipped with a telescopic device for automatically adjusting the peeling amount according to the copper ratio change trend.

4. A method for controlling the copper ratio in the processing of superconducting wire according to claim 1, characterized in that, In Step 4, the specification of the die is smaller than the minimum size of the superconducting wire to be processed with dimensional fluctuations in Step 3.

5. A method for controlling the copper ratio in the processing of superconducting wire materials according to claim 1, characterized in that, After conducting fixed-length peeling on the superconducting wire with the first fluctuation range to the designed copper ratio, conduct stretching, twisting, and stretching to the designed size.

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