Copper ratio control processing method for superconducting wire

Abstract

The invention discloses a processing method for controlling the copper ratio of a superconducting wire, and relates to the technical field of superconducting wire processing, comprising the following steps: acquiring a superconducting wire to be processed; carrying out on-line copper ratio test to obtain a copper ratio change trend and a copper ratio fluctuation range; carrying out coreless lathe scaling according to the copper ratio change trend to obtain a superconducting wire to be processed with fluctuating size; finishing the to-be-processed superconducting wires with fluctuating sizes to a uniform size by using a mold; repeating the online copper ratio test, the coreless lathe peeling and the die finishing until the copper ratio fluctuation range meets the copper ratio fluctuation requirement, and obtaining a superconducting wire in a first fluctuation range; and processing the superconducting wire in the first fluctuation range to a designed copper ratio to obtain a final superconducting wire. On-line copper ratio testing is matched with centreless lathe scaling, so that the copper ratio fluctuation of the superconducting wire is reduced, and the copper ratio uniformity and the performance stability are improved; and non-uniform copper ratio areas at the head and the tail of the wire can be fully utilized, and the yield of the wire is improved.

Description

Technical Field

[0001] The present application relates to the technical field of superconducting wire processing, and in particular to a copper ratio controlled processing method for superconducting wire. Background Art

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

[0003] The conventional processing flow of superconducting wires includes assembly, extrusion and drawing. Among them, extrusion is an important means to achieve effective bonding and diameter reduction of supercomposite materials. During the extrusion process, due to its own processing characteristics, the flow of copper is not completely uniform, especially for the ingot head and ingot tail materials. The actual copper ratio is far from the design 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, the performance margin is large during the design process, the head and tail areas of the wire need to be removed, and the yield rate is low.

[0004] In the prior art, Chinese patent CN104123997A discloses a method for processing a small copper ratio NbTi / Cu superconducting wire, comprising the following steps: stretching a NbTi / Cu single core rod into a NbTi / Cu single core hexagonal rod, cutting and straightening the rod; processing a copper sheath and pickling the rod; arranging the NbTi / Cu single core hexagonal rod in the copper sheath, filling the gaps with copper rods, and sealing the sheath with vacuum electron beam welding to obtain a NbTi / Cu composite sheath; extruding the composite sheath, repeatedly stretching, multiple peeling, and multiple aging heat treatments.

[0005] However, the above-mentioned prior art does not take into account the copper ratio fluctuation of the superconducting wire, and the copper ratio uniformity and performance stability are poor; in addition, the above-mentioned prior art does not consider the utilization of the copper ratio uneven area at the head and tail, and the wire yield is low. Summary of the invention

[0006] The present application provides a copper ratio control processing method for superconducting wires, which is used 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, the utilization of the copper ratio uneven area at the head and tail is not considered, and the wire yield is low.

[0007] In one aspect, the present application provides a method for controlling the copper ratio of a superconducting wire, comprising the following steps: Step 1: Obtain the superconducting wire to be processed.

[0008] Step 2: Perform an online copper ratio test on the superconducting wire to be processed to obtain a copper ratio variation trend and a copper ratio fluctuation range.

[0009] Step three, peeling the superconducting wire to be processed on a centerless lathe according to the variation trend of the copper ratio to obtain a superconducting wire to be processed with fluctuating dimensions.

[0010] Step 4: Use a mold to refine the superconducting wire to a uniform size.

[0011] Step 5, repeating steps 2 to 4 until the copper ratio fluctuation range of the superconducting wire to be processed meets the copper ratio fluctuation requirement, thereby obtaining a superconducting wire with a first fluctuation range.

[0012] Step six, processing the superconducting wire within the first fluctuation range to a designed copper ratio to obtain a final superconducting wire.

[0013] In a possible implementation, step one includes: extruding, stretching, peeling, and stretching the superconducting composite ingot to obtain the superconducting wire to be processed.

[0014] In a possible implementation, in step 2, the online copper ratio test uses an online copper ratio testing device to obtain the copper ratio variation trend of the superconducting wire to be processed along the axial direction, and the minimum copper ratio to the maximum copper ratio in the copper ratio variation trend is the copper ratio fluctuation range.

[0015] In a possible implementation, in step three, the skinning of the centerless lathe adopts a centerless lathe skinning device, and the skinning blade of the centerless lathe skinning device is provided with a retractable device for automatically adjusting the skinning amount according to the change trend of the copper ratio.

[0016] In a possible implementation, in step 4, the specification of the mold is smaller than the minimum size of the superconducting wire to be processed with size fluctuation in step 3.

[0017] In a possible implementation, step six includes: stripping the superconducting wire within the first fluctuation range to a designed copper ratio to obtain a final superconducting wire.

[0018] In a possible implementation, after the superconducting wire in the first fluctuation range is stripped to a designed copper ratio, it is stretched, twisted, and stretched to a designed size.

[0019] A copper ratio controlled processing method for a superconducting wire in the present application has the following advantages: By combining online copper ratio testing with centerless lathe stripping, the copper ratio fluctuation of superconducting wires is reduced, the copper ratio uniformity and performance stability are improved; and the copper ratio uneven area at the head and tail of the wire can be fully utilized to improve the wire yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic flow chart of a method for controlling the copper ratio of a superconducting wire provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] like Figure 1 As shown, the embodiment of the present application provides a copper ratio controlled processing method for a superconducting wire, comprising the following steps: Step 1: Obtain the superconducting wire to be processed.

[0024] Step 2: Perform an online copper ratio test on the superconducting wire to be processed to obtain a copper ratio variation trend and a copper ratio fluctuation range.

[0025] Step three, peeling the superconducting wire to be processed on a centerless lathe according to the variation trend of the copper ratio to obtain a superconducting wire to be processed with fluctuating dimensions.

[0026] Step 4: Use a mold to refine the superconducting wire to a uniform size.

[0027] Step 5, repeating steps 2 to 4 until the copper ratio fluctuation range of the superconducting wire to be processed meets the copper ratio fluctuation requirement, thereby obtaining a superconducting wire with a first fluctuation range.

[0028] Step six, processing the superconducting wire within the first fluctuation range to a designed copper ratio to obtain a final superconducting wire.

[0029] Exemplarily, step one includes: extruding, stretching, peeling, and stretching the superconducting composite ingot to obtain the superconducting wire to be processed.

[0030] Specifically, the peeling in step 1 is to remove the oxide scale on the surface of the superconducting composite ingot.

[0031] Exemplarily, in step 2, the online copper ratio test uses an online copper ratio testing device to obtain the copper ratio variation trend of the superconducting wire to be processed along the axial direction, and the minimum copper ratio to the maximum copper ratio in the copper ratio variation trend, that is, the copper ratio fluctuation range.

[0032] Exemplarily, in step three, the skinning of the centerless lathe adopts a centerless lathe skinning device, and the skinning blade of the centerless lathe skinning device is provided with a retractable device for automatically adjusting the skinning amount according to the change trend of the copper ratio.

[0033] Specifically, in step three, the stripping speed of the centerless lathe can be adjusted within the range of 2-15m / min according to actual conditions to ensure that the stripping area is repeated and continuous.

[0034] Exemplarily, in step 4, the specification of the mold is smaller than the minimum size of the superconducting wire to be processed with size fluctuation in step 3.

[0035] Exemplarily, step six includes: stripping the superconducting wire within the first fluctuation range to a designed copper ratio to obtain a final superconducting wire.

[0036] Exemplarily, after the superconducting wire in the first fluctuation range is stripped to a designed copper ratio, it is stretched, twisted, and stretched to a designed size.

[0037] Embodiment 1: This embodiment provides an implementation process for obtaining a finished wire having a designed copper ratio of 1.500±0.050: Step 1: Extrude, stretch, 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 3.000 mm.

[0038] Step 2: Use an online copper ratio testing device to perform an online copper ratio test on the superconducting wire to be processed in step 1 to obtain the copper ratio change trend and copper ratio fluctuation range of the superconducting wire to be processed along the axial direction, and the copper ratio fluctuation range is 2.200-4.300.

[0039] Step three, using a centerless lathe stripping device to strip the superconducting wire to be processed in step two according to the change trend of the copper ratio, to obtain a superconducting wire to be processed with a size fluctuation of 2.330-3.000 mm in diameter.

[0040] Step 4: Use a die with a specification of 2.19 mm to finely trim the superconducting wire with size fluctuations in step 3 to a diameter of 2.19 mm, and the size accuracy after trimming is within the range of ±0.002 mm. At this time, the copper ratio fluctuation range is 2.100-2.300.

[0041] Step 5, repeat steps 2 to 4 (a new specification of mold will be selected according to the new size fluctuation during the repetition of step 4) 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), and the diameter of the superconducting wire in the first fluctuation range is obtained to be 2.011 mm, and the copper ratio fluctuation range is 1.685-1.715.

[0042] Step six, the superconducting wire in the first fluctuation range obtained in step five is stripped to a diameter of 1.936 mm, and the copper ratio fluctuation range at this time is 1.450-1.550, and then stretched, twisted, and stretched to the designed size to obtain a final superconducting wire with a diameter of 0.542 mm, a copper ratio fluctuation range of 1.450-1.550, and a finished product rate of 85% (the finished product rate of conventional superconducting composite ingots processed to this copper ratio fluctuation range is 80%).

[0043] Embodiment 2: This embodiment provides an implementation process for obtaining a finished wire having a designed copper ratio of 4.600±0.050: Step 1: Extrude, stretch, 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.

[0044] Step 2: Use an online copper ratio testing device to perform an online copper ratio test on the superconducting wire to be processed in step 1 to obtain the copper ratio change trend and copper ratio fluctuation range of the superconducting wire to be processed along the axial direction, and the copper ratio fluctuation range is 5.300-9.800.

[0045] Step three, a centerless lathe stripping device is used to strip the superconducting wire to be processed in step two according to the change trend of the copper ratio, so as to obtain a superconducting wire to be processed with a size fluctuation of 5.217-6.831 mm in diameter.

[0046] Step 4: Use a die with a specification of 5.150 mm to finely trim the superconducting wire to be processed in step 3 with a diameter of 5.150 mm, and the dimensional accuracy after trimming is within the range of ±0.002 mm. At this time, the copper ratio fluctuation range is 4.870-5.120.

[0047] Step 5, repeat steps 2 to 4 (a new specification of mold will be selected according to the new size fluctuation during the repetition of step 4) 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), and the diameter of the superconducting wire in the first fluctuation range is obtained to be 3.500 mm, and the copper ratio fluctuation range is 4.750-4.830.

[0048] Step six, the superconducting wire in the first fluctuation range obtained in step five is stripped to a diameter of 3.442 mm, and the copper ratio fluctuation range at this time is 4.550-4.650, and then stretched, twisted, and stretched to the designed size to obtain a 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%).

[0049] The embodiment of the present application reduces the copper ratio fluctuation of superconducting wires and improves the copper ratio uniformity and performance stability by combining online copper ratio testing with centerless lathe stripping; and can fully utilize the copper ratio uneven area at the head and tail of the wire to improve the wire yield.

[0050] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0051] 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 equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for controlling the copper ratio of a superconducting wire, characterized in that: The following steps are involved: Step 1, obtaining a superconducting wire to be processed; Step 2, performing an online copper ratio test on the superconducting wire to be processed to obtain a copper ratio variation trend and a copper ratio fluctuation range; Step 3, stripping the superconducting wire to be processed by a centerless lathe according to the change trend of the copper ratio to obtain a superconducting wire to be processed with fluctuating dimensions; Step 4, using a mold to refine the superconducting wire to be processed with fluctuating dimensions to a uniform size; Step 5, repeating steps 2 to 4 until the copper ratio fluctuation range of the superconducting wire to be processed meets the copper ratio fluctuation requirement, thereby obtaining a superconducting wire of a first fluctuation range; Step six, processing the superconducting wire within the first fluctuation range to a designed copper ratio to obtain a final superconducting wire.

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

3. The copper ratio controlled processing method of a superconducting wire according to claim 1, characterized in that: In step 2, the online copper ratio test uses an online copper ratio test device to obtain the copper ratio change trend of the superconducting wire to be processed along the axial direction, and the minimum copper ratio to the maximum copper ratio in the copper ratio change trend is the copper ratio fluctuation range.

4. The copper ratio controlled processing method of a superconducting wire according to claim 1, characterized in that: In step three, the centerless lathe peeling adopts a centerless lathe peeling device, and the peeling blade of the centerless lathe peeling device is equipped with a retractable device for automatically adjusting the peeling amount according to the change trend of the copper ratio.

5. The copper ratio controlled processing method of a superconducting wire according to claim 1, characterized in that: In step 4, the specification of the mold is smaller than the minimum size of the superconducting wire to be processed with size fluctuation in step 3.

6. The copper ratio controlled processing method of a superconducting wire according to claim 1, characterized in that: Step six includes: stripping the superconducting wire within the first fluctuation range to a predetermined length to a designed copper ratio to obtain a final superconducting wire.

7. A method for controlling the copper ratio of a superconducting wire according to claim 6, characterized in that: After the superconducting wire in the first fluctuation range is stripped to a designed copper ratio, it is stretched, twisted, and stretched to a designed size.

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