阅读说明：本技术 一种测量超导带材临界弯曲半径的装置和方法 (Device and method for measuring critical bending radius of superconducting tape ) 是由 张展 刘啸 刘华军 宋云涛 施毅 刘方 秦经刚 王其其 于 2021-08-23 设计创作，主要内容包括：本发明公开了一种测量超导带材临界弯曲半径的装置和方法。测量装置由一个变半径线圈模具、一个热处理卡装结构和一个样品杆组成,其中变半径线圈模具是核心部件,其包含不锈钢模具和铜模具两部分,形状都由多个不同半径大小的半圆环相接而成。带材在不锈钢模具上进行绕制,绕成的带材便在不同区段上具有不同的弯曲半径,然后将该部分放进卡装结构中进行热处理。取出热处理后的线圈,焊接在铜模具的缝隙中,然后将铜模具安装在样品杆上。半圆环之间的连接处为测量点,通过对这些点的测量便可知晓哪些圆环发生了失超,从而可以利用该发明装置来确定超导带材在设定条件下可允许的最小弯曲半径。(The invention discloses a device and a method for measuring the critical bending radius of a superconducting tape. The measuring device consists of a variable-radius coil mould, a heat treatment clamping structure and a sample rod, wherein the variable-radius coil mould is a core part and comprises two parts, namely a stainless steel mould and a copper mould, and the shape of the variable-radius coil mould is formed by connecting a plurality of semicircular rings with different radiuses. The strip was wound on a stainless steel die, the wound strip having different bend radii at different sections, and the section was then placed in a clamped configuration for heat treatment. And taking out the heat-treated coil, welding the heat-treated coil in a gap of a copper mold, and then mounting the copper mold on a sample rod. The joints between the semi-circular rings are measuring points, and the measuring of the points can know which circular rings are quenched, so that the device can be used for determining the minimum allowable bending radius of the superconducting strip under set conditions.)

1. An apparatus for measuring critical bending radius of a superconducting tape, comprising: comprises a variable radius coil mould, a heat treatment clamping structure and a sample rod; the variable radius coil mould comprises a copper mould and a stainless steel mould, the shape of the variable radius coil mould is formed by combining a plurality of semicircular rings with gradually increased radii, and the variable radius coil mould is used for winding a strip on the stainless steel mould to form a spiral linear strip with a plurality of bending radii;

the heat treatment clamping structure is provided with a clamping groove and is used for placing a stainless steel die wound with a strip material for heat treatment;

a copper mould in the variable-radius coil mould is arranged at the upper part of the sample rod, the copper mould is provided with a gap for embedding a heat-treated strip, and the strip is welded in the gap of the copper mould;

two ends of the strip are connected with current leads on the test platform, signal lines are connected to measuring points on the strip, and the U-I curve on each section of the strip can be measured after the load is set.

2. The apparatus for measuring critical bending radius of a superconducting tape according to claim 1, wherein: the stainless steel mould comprises the semicircle ring segment of a plurality of splittable, the coiling and the taking out of band material of being convenient for, and each semicircle ring segment radius is different, and the semicircle ring of each segment is connected through the screw hole at both ends, forms helical structure.

3. The apparatus for measuring critical bending radius of a superconducting tape according to claim 1, wherein: and a layer of glass fiber tape is wound on each of two sides of the strip material to prevent the strip material from being adhered to a stainless steel die after heat treatment.

4. The apparatus for measuring critical bending radius of a superconducting tape according to claim 1, wherein: the copper mould is provided with a gap with a spiral structure and used for fixing a strip, a hole is formed in the copper mould, and the copper mould is connected to the mounting platform on the sample rod through a bolt.

5. The apparatus for measuring critical bending radius of a superconducting tape according to claim 1, wherein: the heat treatment clamping structure is provided with a plurality of bolt holes and bolts, and the inner groove is of a circular structure and is used for being assembled with a stainless steel die.

6. The apparatus for measuring critical bending radius of a superconducting tape according to claim 1, wherein: the semi-circle segments are in tangent transition, so that the strip is in continuous smooth transition in the bending process, and each tangent point is set as a measuring point of the strip.

7. The apparatus for measuring critical bending radius of a superconducting tape according to claim 1, wherein: the sample rod comprises an installation platform, a current lead and a signal wire, wherein the current lead ports are arranged at the positive and negative electrodes on the installation platform, the positive and negative electrodes are respectively connected with the center and the outer port of the strip winding die, and the signal wire is connected to the measuring point of the strip; the disc at the outermost end of the sample rod is an installation platform, and two holes are formed in the upper end of the disc and used for installing and fixing the copper mold.

8. A method for measuring a critical bending radius of a superconducting tape, comprising the steps of:

step 1) winding a layer of glass fiber band on a stainless steel mold, then winding the band, finally winding a layer of glass fiber band, then pre-tightening bolts and nuts between small sections, and fixing the whole stainless steel mold;

step 2) in the heat treatment stage of the strip, putting the stainless steel mold wound with the strip in a furnace for heat treatment, splitting the stainless steel mold into a plurality of small sections through bolts after the heat treatment is finished, and taking out the strip;

step 3) in the equipment assembling stage, the strip after heat treatment is disassembled from the stainless steel mould and welded on the copper mould, and mica is filled between the strip and the copper mould; the copper mould is provided with a hole, the copper mould and the mounting platform of the sample rod are connected together through a bolt, the center of the copper mould and the outer end of the strip material are respectively spot-welded at the positive and negative positions on the sample rod and connected with a current lead;

and 4) in the measurement stage, the tangent point of the joint of the circular rings with different radii is set as a measurement point, the signal line on the sample rod is spot-welded to the measurement point, and the voltage on each semi-circular ring is measured, so that which semi-circular rings are subjected to quenching, and the critical bending radius range of the strip is obtained.

Technical Field

The invention relates to the technical field of performance measurement and test of superconducting materials, in particular to a device and a method for quickly and efficiently measuring the critical bending radius of a superconducting tape, which are applied to measuring the critical bending radius of a high-temperature superconducting tape.

Background

The high-temperature superconducting material has the advantages of high critical temperature, high critical magnetic field, high current-carrying capacity and the like, so that the high-temperature superconducting material has wide application prospects in the fields of superconducting cables, high-field magnets, accelerators and the like, and the superconducting tape is often in a bent state in the practical application of the fields, but due to the laminated structure and characteristics of the high-temperature superconducting material, the current-carrying performance is reduced and even the superconductivity is lost due to the bending of the tape.

The existing high-temperature strip critical bending radius measuring method is only to change the shape of the strip to carry out repeated measurement, although the method is not very complicated for the YBCO wire strip, the repeated assembly, heat treatment, disassembly and assembly, measurement and other processes are particularly complicated for the superconducting materials needing heat treatment, such as iron base and Bi2223, and the disassembly and assembly often damage the quality of a sample. Therefore, the critical bending radius of the high-temperature superconducting tape can be efficiently and quickly measured, and the performance of the high-temperature superconducting tape can be further researched to promote the development of the high-temperature superconducting tape in various fields.

Disclosure of Invention

The invention aims to provide a device and a method for measuring the critical bending radius of a superconducting tape, in particular to a superconducting tape which is iron-based, Bi2223 and the like and needs to be subjected to heat treatment, and the critical bending radius range of the tape under set conditions can be measured efficiently and quickly. The device comprises a variable-radius coil die, a heat treatment clamping structure and a sample rod, wherein a core component strip winding die is composed of copper and stainless steel, the shape of the core component strip winding die is formed by combining a plurality of semicircular rings with gradually increased radii, the strips are continuously and smoothly transited among different radii and wound on the stainless steel die, so that the strips have different bending radii in different sections, and the critical bending radius range of the high-temperature superconducting strips under set conditions can be measured.

The technical scheme of the invention is as follows: a device for measuring the critical bending radius of a superconducting tape comprises a variable radius coil mould, a heat treatment clamping structure and a sample rod; the variable radius coil mould comprises a copper mould and a stainless steel mould, the shape of the variable radius coil mould is formed by combining a plurality of semicircular rings with gradually increased radii, and the variable radius coil mould is used for winding a strip on the stainless steel mould to form a spiral linear strip with a plurality of bending radii;

the clamping structure is provided with a clamping groove and is used for placing a stainless steel die wound with a strip for heat treatment;

a copper mould in the variable-radius coil mould is arranged at the upper part of the sample rod, the copper mould is provided with a gap for embedding a heat-treated strip, and the strip is welded in the gap of the copper mould;

two ends of the strip are connected with current leads on the test platform, signal lines are connected to measuring points on the strip, and the U-I curve on each section of the strip can be measured after the load is set.

Further, the stainless steel mould comprises the semicircle ring segment of a plurality of splittable, the coiling and the taking out of strip of being convenient for, and each semicircle ring segment radius is different, and the semicircle ring of each segment is connected through the screw hole at both ends, forms helical structure.

Furthermore, a layer of glass fiber tape is wound on each side of the strip material, so that the strip material is prevented from being adhered to a stainless steel mold after heat treatment.

Furthermore, a gap with a spiral structure is formed in the copper die and used for fixing the strip, a hole is formed in the copper die, and the copper die is connected to the mounting platform on the sample rod through a bolt.

Furthermore, the semi-circle segments are in tangent transition, so that the strip is in continuous smooth transition in the bending process, and each tangent point is set as a measuring point of the strip.

Furthermore, the sample rod comprises an installation platform, a current lead and a signal wire, wherein the current lead ports are arranged at the positive and negative electrodes on the installation platform, the positive and negative electrodes are respectively connected with the center and the outer port of the strip winding die, and the signal wire is connected to the measuring point of the strip; the disc at the outermost end of the sample rod is an installation platform, and two holes are formed in the upper end of the disc and used for installing and fixing the copper mold.

According to another aspect of the present invention, there is provided a method of measuring a critical bending radius of a superconducting tape, comprising the steps of:

step 1) winding a layer of glass fiber band on a stainless steel mold, then winding the band, finally winding a layer of glass fiber band, then pre-tightening bolts and nuts between small sections, and fixing the whole stainless steel mold;

step 2) in the heat treatment stage of the strip, putting the stainless steel mold wound with the strip in a furnace for heat treatment, splitting the stainless steel mold into a plurality of small sections through bolts after the heat treatment is finished, and taking out the strip;

step 3) in the equipment assembling stage, the strip after heat treatment is disassembled from the stainless steel mould and welded on the copper mould, and mica is filled between the strip and the copper mould; the copper mould is provided with a hole, the copper mould and the mounting platform of the sample rod are connected together through a bolt, the center of the copper mould and the outer end of the strip material are respectively spot-welded at the positive and negative positions on the sample rod and connected with a current lead;

and 4) in the measurement stage, the tangent point of the joint of the circular rings with different radii is set as a measurement point, the signal line on the sample rod is spot-welded to the measurement point, and the voltage on each semi-circular ring is measured, so that which semi-circular rings are subjected to quenching, and the critical bending radius range of the strip is obtained.

Compared with the prior art, the invention has the beneficial effects that:

the invention is not limited to a specific material, and the heat treatment process of the strip can be completed by only one process without repeating the processes of packaging, firing, dismounting and the like for multiple times in the heat treatment stage like the traditional method.

The strip material after heat treatment of the device is convenient to take out, and the complete strip material can be obtained only by taking out the bolts and the nuts between the small sections of the stainless steel mould, so that the quality of the strip material cannot be damaged.

According to the invention, a plurality of strip samples are not required to be wound, and the determination of the critical bending radius range of the strip can be quickly and efficiently completed by only one tool, so that a large amount of time and cost are saved.

Drawings

FIG. 1 is a stainless steel mold in the apparatus of the present invention;

FIG. 2 is a copper mold in the apparatus of the present invention;

FIG. 3 is a sample rod;

FIG. 4 is a snap fit configuration;

fig. 5 shows the assembly of the sample rod and the copper mold.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the prior art solutions, the drawings that are needed in the description of the prior art and the embodiments will be briefly described below.

According to an embodiment of the invention, the device for measuring the critical bending radius of the superconducting tape comprises a variable radius coil mould, a heat treatment clamping structure and a sample rod; the variable radius coil mould comprises a copper mould and a stainless steel mould, the shape of the variable radius coil mould is formed by combining a plurality of semicircular rings with gradually increased radiuses, and the different radiuses are in continuous and smooth transition and are used for winding a strip on the stainless steel mould to be wound into a spiral linear strip with a plurality of bending radiuses and testing on the copper mould;

the heat treatment clamping structure is provided with a clamping groove and is used for placing a stainless steel die wound with a strip material for heat treatment;

a copper mould in the variable-radius coil mould is arranged at the upper part of the sample rod, the copper mould is provided with a gap for embedding a heat-treated strip, and the strip is welded in the gap of the copper mould;

two ends of the strip are connected with current leads on the test platform, signal lines are connected to measuring points on the strip, and the U-I curve on each section of the strip can be measured after the load is set.

According to an embodiment of the invention, as shown in fig. 1, the stainless steel mold for winding the strip in the device of the invention is formed by connecting a plurality of semicircular segments, so that the winding and the disassembly of the strip are convenient, the semicircular segments are in tangential transition, and therefore the strip is in continuous and smooth transition in the bending process, and each tangential point is set as a measuring point of the strip. After the strip is subjected to heat treatment and is detached, the strip is welded in a gap of a copper mold, and mica insulation is filled between the strip and the inner layer copper mold. And finally, assembling the copper mould and the sample rod through two small holes in the copper mould.

FIG. 3 is a sample rod comprising a mounting platform, current leads and signal wires. The current lead ports are arranged at the positive and negative electrodes on the mounting platform, the positive and negative electrodes are connected with the center and the outer port of the strip winding die, and the signal wire is connected with the measuring point of the strip. The disc at the outermost end of the sample rod is an installation platform, and two holes are formed in the upper end of the disc and used for installing and fixing the copper mold.

Fig. 4 shows a clamping structure with a plurality of bolt holes and bolts, and an internal groove for assembling with a strip winding mold. The clamping structure is internally provided with a small opening circle, so that the groove can be slightly enlarged, the installation of the die is convenient, and the outer end of the clamping structure is pre-tightened through bolts and nuts.

According to an embodiment of the present invention, there is also provided a method for measuring a critical bending radius of a superconducting tape using the aforementioned apparatus, including the steps of:

step 1) winding a layer of glass fiber band on a stainless steel mold, then winding the band, finally winding a layer of glass fiber band, then pre-tightening bolts and nuts between small sections, and fixing the whole stainless steel mold;

step 2) in the heat treatment stage of the strip, the stainless steel die wound with the strip is placed in a furnace together for heat treatment, the heat treatment of the device has the great advantage that a plurality of packages, heat treatments and disassembly and assembly are required in the traditional mode, the sample is often easily damaged in the disassembly and assembly process, and after the heat treatment of the device is completed, the stainless steel framework can be disassembled into a plurality of small sections through bolts, so that the strip can be conveniently taken out and cannot be adhered to the stainless steel die;

step 3) in the equipment assembling stage, the strip after heat treatment is disassembled from the stainless steel mould and welded on the copper mould, and mica is filled between the strip and the copper mould; the copper mould is provided with a hole, the copper mould and the mounting platform of the sample rod are connected together through a bolt, the center of the copper mould and the outer end of the strip material are respectively spot-welded at the positive and negative positions on the sample rod and connected with a current lead;

and 4) in the measuring stage, the tangent point of the joint of the circular rings with different radii is set as a measuring point, the signal line on the sample rod is spot-welded to the measuring point, and the voltage on each half circular ring is measured, so that which half circular rings are subjected to quenching is judged, and the critical bending radius range of the strip is obtained.

Although illustrative embodiments of the present invention have been described above to facilitate the understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the embodiments, but various changes may be apparent to those skilled in the art, and it is intended that all inventive concepts utilizing the inventive concepts set forth herein be protected without departing from the spirit and scope of the present invention as defined and limited by the appended claims.