Method of manufacturing superconducting wire

FIELD: electricity.

SUBSTANCE: invention is related to the method of manufacturing superconducting wire, in particular, to the method of manufacturing superconducting wire with high and uniform working characteristics. Method includes stage (S3) of wire dragging in the form of metal-clad powder of superconducting material, stage (S8) of primary rolling of multiple-strand wire after stage (S3) of wire dragging and stage (S10) of primary caking of multiple-strand wire after stage (S8) of primary rolling. At least, between stage (S3) of wire dragging and stage (S8) of primary rolling or between stage (S8) of primary rolling and stage (S10) of primary caking the stages (S4, S7, S9) are stipulated for keeping of metal-clad wire and multiple-strand wire or only multiple-strand wire in reduced pressure atmosphere. Because of this, the superconducting wire with high and uniform working characteristics will be received, which is the technical result of the invention.

EFFECT: manufacturing of superconducting wire with high and uniform working characteristics.

11 cl, 8 dwg, 3 tbl, 3 ex

 

The technical field

The present invention relates to a method of manufacturing a superconducting wire and, in particular, to a method of manufacturing a superconducting wire according to which it is possible to obtain a superconducting wire with high and uniform operating characteristics.

The level of technology

It is generally assumed that the superconducting wire, made in the form of stranded wires formed by cladding a metal oxide superconductor having, for example, the Bi2223 phase, will be used in the superconducting cable and the magnet, as it can be used at the temperature of liquid nitrogen, and can be achieved relatively high critical current density, and it can be a relatively simple way longer.

Such a superconducting wire was produced as described below. First, make a wire having a shape in which the powder source material for a superconductor containing a phase, as Bi2223, plated metal. After that, by repeatedly performing the heat treatment and rolling was formed superconducting phase aligned to the superconducting wires of the wire, and thus was obtained a ribbon-like superconducting wire. Such a method of manufacturing a superconducting wire is disclosed, for example, the R, in Japanese patent No. 2636049 (publication of Japanese patent No. 03-138820) (patent document 1) and Japanese patent No. 2855869 (publication of Japanese patent No. 04-292812) (patent document 2).

Disclosure of invention

Objectives of the invention

To date traditionally led the search for optimal conditions of production for each process stage in order to improve performance (such as the critical current) of the superconducting wire. However, even if the superconducting wire is manufactured under the same optimal conditions, the obtained superconducting wire has variations in each performance. Moreover, some of the obtained superconducting wires have poor performance, and, therefore, cannot be obtained superconducting wire with high performance.

Therefore, the present invention is to develop a method of manufacturing a superconducting wire, which gives the opportunity to obtain a superconducting wire with high and uniform operating characteristics.

Means for solving these problems

A method of manufacturing a superconducting wire according to one aspect of the present invention includes a phase lug wire formed placer the requirement of the powder starting material for the superconductor metal, rolling wire after the stage of drawing, and sintering the wire after the stage of rolling. This method additionally includes the stage of holding the wire in an atmosphere of reduced pressure in the at least one gap between the stage lug and the stage of rolling and the gap between the stage and rolling stage sintering.

After careful study, the authors present invention found that the obtained superconducting wire has deviations in each of the performance for reasons that will be described below. In each of the intervals between stages of drawing, rolling and sintering in the wire are present in the air CO2(carbon dioxide), N2On (water), O2(oxygen) and similar substances through both end part of the wire or through the metal shell of the superconductor. This leads to the formation during sintering of heterophase, non-superconducting phases, or to uneven thickness of the wire. Education heterophase during sintering prevents the formation of the superconducting phase and degrades the superconducting properties such as critical current. Moreover, if the wire has a non-uniform thickness, the pressure when performed later by rolling is applied to the wire unevenly, and therefore the obtained superconducting wire has a non-uniform that is a woman. In the worse performance of the superconducting wire. Usually, the conditions of exposure of the wire between the stage of drawing and stage rolling or between the stage and rolling stage sintering is not specifically regulated. Therefore, the obtained superconducting wire had deviations for each of the performance-dependent differences in the conditions of exposure.

Therefore, by holding the wire in an atmosphere of reduced pressure in at least one of the intervals between stages of drawing, rolling and sintering can be suppressed from entering into the powder source material present in the air CO2N2O2. Moreover, when the exposure wire in an atmosphere of reduced pressure remains substances such as CO2N2O2and so, inside the wire, is displayed through the ends of the wire or through the metal shell of the superconductor. As a result, heterophase during sintering will produce less likely, and the wire will have a uniform thickness, and, thus, can be obtained superconducting wire having high and uniform operating characteristics.

A method of manufacturing a superconducting wire according to another aspect of the present invention includes a phase lug wire, arr is organised by the cladding powder source material for the superconductor metal, rolling wire n times (n is an integer not less than 2), and sintering the wire n times. The first stage of rolling on the stage of rolling the wire n times carry out after the stage of drawing. The first stage of sintering at the sintering step and the wire n times performed after the first stage of rolling. Stage k-th (k is an integer satisfying n ≥ k ≥ 2) rolling on the stage of rolling the wire n times performed after stage (k-1)-th sintering in the sintering step and the wire n times. Stage k-th sintering in the sintering step and the wire n times do after stage k-th rolling on the stage of rolling the wire n times. The method additionally includes the stage of holding the wire in an atmosphere of reduced pressure in at least one of the gap between the stage lug and the first stage of the rolling gap between the stage of the first rolling and the first stage of sintering, the gap between the stage (k-1)-th sintering and phase of the k-th rolling and the gap between stage k-th rolling and phase of the k-th sintering.

After careful study, the authors present invention found that the obtained superconducting wire has deviations in each of the performance for reasons that will be described below. When manufacturing a superconducting wire execute stage rolling wire n times and the stage of sintering wire n times present in the air CO2(dioxy the carbon), H2On (water), O2(oxygen) and similar substances in powder source material through both end part of the wire or through the metal shell of the superconductor between stage lug and the first stage of rolling, in the interval between the stage of the first rolling and the first stage of sintering, between stage (k-1)-th sintering and phase of the k-th rolling mill and between stage k-th rolling and phase of the k-th sintering. As a result, deteriorate the performance characteristics of superconducting wires as described above. Usually, when performing the stage of rolling the wire n times and the sintering step and the wire n times the conditions of the exposure wire in between stage lug and the first stage of rolling, between stage (k-1)-th sintering and phase of the k-th rolling mill and between stage k-th rolling and phase of the k-th sintering is not specifically regulated. Therefore, the obtained superconducting wire had deviations for each of the performance-dependent differences in the conditions of exposure.

Therefore, by holding the wire in an atmosphere of reduced pressure in the at least one gap between the stage lug and the first stage of the rolling gap between the stage of the first rolling and the first stage of sintering, the gap between the stage (k-1)-th sintering and what tadia k-th rolling and the gap between stage k-th rolling and phase of the k-th sintering, can be suppressed from entering into the powder source material present in the air CO2N2O, and o2. Moreover, when the exposure wire in an atmosphere of reduced pressure remains substances such as CO2N2O2and so, inside the wire, is displayed through both end part of the wire or through the metal shell of the superconductor. As a result, heterophase during sintering will produce less likely, and the wire will have a uniform thickness, and, thus, can be obtained superconducting wire having high and uniform operating characteristics.

Preferably, in the method of manufacturing a superconducting wire according to another aspect of the present invention stage exposure is performed in the interval between the stage of the first rolling and the first stage of sintering.

The authors of the present invention found that present in the air CO2N2O, and o2less likely to fall into the powder source material in the gap between the stage of the first rolling and the first stage of sintering. Therefore, it may be obtained superconducting wire having a higher and more uniform performance.

Preferably in the method of manufacturing a superconducting wire according to the present invention at Opera reduced pressure has a pressure of not more than 0.01 MPa. Thereby can be further suppressed from entering present in the air CO2N2O, and o2in the superconductor.

Preferably, in the method of manufacturing a superconducting wire according to the present invention stage extracts perform for at least 72 hours. Thereby remains contained inside the wire can be removed sufficiently.

Preferably in the method of manufacturing a superconducting wire according to the present invention at the stage extracts the wire is maintained at a temperature of at least 80°C. This promotes evaporation residues contained within the wire, and thus, can be obtained superconducting wire having high and uniform operating characteristics.

Preferably, in the method of manufacturing a superconducting wire according to the present invention stage exposure is performed in the atmosphere of gaseous nitrogen, gaseous argon or dry air.

This can prevent impurities such as CO2N2O2and so, in the powder source material during the stage of exposure.

It should be noted that rolling and sintering in the present invention can be executed only once, or may be executed many times (n times). Moreover, in this description, you shall agenie "first rolling" refers to the stage of rolling the wire for the first time, and the expression "the first sintering" refers to the stage of sintering wire for the first time. When the stage of drawing is performed in relation to the wire many times, the expression "stage drawing" refers to the first drawing performed on the wire. Moreover, the expression "dry air" refers to air having a dew point at atmospheric pressure of not more than -20°C.

The results of the invention

According to the method of manufacturing a superconducting wire of the present invention, can be suppressed from entering present in the air CO2N2O, and o2the wire in each of the intervals between stages of the drawing, the first rolling and the first sintering. Moreover, by holding the wire in an atmosphere of reduced pressure remains substances such as CO2N2O2and so, inside the wire, is displayed through both end part of the wire or through the metal shell of the superconductor. As a result, heterophase during sintering will produce less likely, and the wire will have a uniform thickness, and, thus, can be obtained superconducting wire having high and uniform operating characteristics.

Brief description of drawings

Figure 1 is a fragmentary perspective view in section illustrating the structure of a superconducting wire is on a conceptual basis.

Figure 2 is a block diagram illustrating a method of manufacturing a superconducting wire in one variant embodiment of the present invention.

Figure 3 is a first view illustrating a stage in Figure 2.

4 is a second view illustrating a stage in Figure 2.

5 is a third view illustrating a stage in Figure 2.

6 is a fourth view illustrating a stage in Figure 2.

7 is a fifth view illustrating a stage in Figure 2.

Fig - sixth view illustrating a stage in Figure 2.

Description reference position on drawings

1 is a superconducting wire (stranded wire), 1A - wire (wire), 1b - clad wire (covered with wire), 1C - stranded wire, 2 - superconducting lived, 2A - powder starting material, 3 - shell, 3A, 3b - tube 20 - Luggage, 21 and exhaust channel, 22 - holder, 23 - heater.

The best ways of carrying out the invention

Below will be described variant embodiment of the present invention with reference to the drawings.

Figure 1 is a fragmentary perspective view with a cross section illustrating the structure of a superconducting wire on a conceptual basis. With reference to figure 1 for an example will be given an explanation of superconducting wire. The superconducting wire 1 has many superconducting lived 2 extending in the longitudinal direction, and covering and the shell 3. Each of the multiple superconducting lived 2 is made of material having a composition of, for example, from a system of Bi-Pb-Sr-Ca-Cu-O, and, in particular, an optimum material is a material containing a Bi2223 phase, in which the atomic ratio (bismuth and lead):strontium:calcium:copper represented approximately as 2:2:2:3. The shell 3 is made of such material as silver.

It should be noted that although this explanation was given with reference to a stranded wire can be used an oxide superconducting wire having a core structure, in which the only superconducting lived 2 coated 3.

Next will be explained a method of manufacturing the above-described oxide superconducting wire.

Figure 2 is a block diagram illustrating a method of manufacturing a superconducting wire in one variant embodiment of the present invention. 3 to 8 illustrate respective stages of figure 2.

Referring to figure 2, for the manufacture of superconducting wire, for example, Bi2223 phase, use the method of "powder in tube". First, for example, mix five types of powders of starting materials (Bi2About3, PbO, SrCO3, CaCO3, CuO) to obtain the powder source material in an intermediate state (powder predecessor), which will eventually be turned into a superconductor with f is zo Bi2223 in the reaction, caused by heat treatment (stage S1).

After that, as shown in figure 2 and 3, this powder 2A source material fill tube 3A (stage S2). Tube 3A is made of metal, such as silver, has an outer diameter ⊘20-40 mm and a wall thickness of about 3-15% of the outer diameter. Thus, get the wire 1A, in which the powder 2A source material for the superconductor-plated tube 3A. Then perform the degassing of the contents of the tube 3A and seal both ends of the tube 3A.

After that, as shown in figure 2 and 4, the wire 1A is subjected to drawing with the formation of the clad wire 1b, in which the precursor in the form of filamentary material covered (coated) metal, such as silver (stage S3). Clad wire 1b has the shape of a hexagon with the distance between the opposite sides, comprising, for example, 2-10 mm.

After that, as shown in figure 2 and 5, the clad wire 1b is kept on the holder 22 in the chamber 20, for example, for at least 72 hours (stage S4). The camera 20 has an exhaust channel 21, and the exhaust channel 21 is connected to a vacuum pump (not shown). The air inside the chamber 20 is evacuated by a vacuum pump through an exhaust channel 21, so that the inside of the chamber 20 is maintained atmosphere of reduced pressure, for example, not more than 0.01 MPa. Moreover, inside the chamber 20 presets is there atmosphere, for example, gaseous nitrogen, gaseous argon or dry air. Moreover, inside the holder 22 includes a heater 23 for heating the clad wire 1b, survive on the holder 22, to a temperature of, for example, at least 80°C. Since the clad wire 1b is kept in the atmosphere of reduced pressure, can be suppressed from entering present in the air CO2N2O2etc. in powder 2A of the source material. Moreover, it can be inferred CO2N2O2and so, the present inside clad wire 1b.

After that, as shown in figure 2 and 6, many clad wire 1b is collected in a bun, inserted into the tube 3b, made of metal, such as silver (stranded Assembly: stage S5). This tube 3b is made of metal, such as silver or its alloy, has an outer diameter ⊘10-50 mm and a wall thickness of about 1-15% of the outer diameter. Thus, the receive wire with stranded structure with many lived, made of powder 2A of the source material.

After that, as shown in figure 2 and 7, the wire with stranded structure in which many lived, made of powder 2A of the source material, coated 3, is subjected to drawing with the formation of stranded wire 1C, in which the powder 2A source the th material sealed inside the shell 3, performed, for example, silver (stage S6).

After that, as shown in figure 2 and 5, a stranded wire 1C is kept on the holder 22 in the chamber 20 in an atmosphere of reduced pressure, for example, for at least 72 hours (stage S7). Inside the chamber 20 there is an atmosphere, for example, gaseous nitrogen, gaseous argon or dry air. Because stranded wire 1C is kept in the atmosphere of reduced pressure, can be suppressed from entering present in the air CO2N2O2etc. in powder 2A of the source material. Moreover, it can be inferred CO2N2O2and so, the present inside stranded wire 1C.

After that, as shown in figure 2 and 8, for stranded wire 1C perform the first rolling with getting stranded ribbon wire 1 (stage S8). The first rolling is carried out by compression, for example, 70-90%.

After that, as shown in figure 2 and 5, a stranded wire 1 is kept on the holder 22 in the chamber 20 in an atmosphere of reduced pressure, for example, for at least 72 hours (stage S9). Inside the chamber 20 there is an atmosphere, for example, gaseous nitrogen, gaseous argon or dry air. Because stranded wire 1 is kept in an atmosphere of reduced pressure, can be suppressed from entering present in ozdok CO 2N2O2etc. in powder 2A of the source material. Moreover, it can be inferred CO2N2O2and so, the present inside stranded wire 1.

Then the ribbon shaped stranded wire 1 is heated to a temperature of, for example, 830-850°C and maintained at this temperature for 50-150 hours, and thus stranded wire 1 is subjected to a first sintering (stage S10). Thus, the powder 2A source material chemically reacts and becomes superconducting residential 2.

After that, as shown in figure 2 and 5, a stranded wire 1 is kept on the holder 22 in the chamber 20 in an atmosphere of reduced pressure, for example, for at least 72 hours (stage S11). Inside the chamber 20 there is an atmosphere, for example, gaseous nitrogen, gaseous argon or dry air. Because stranded wire 1 is kept in an atmosphere of reduced pressure, can be suppressed from entering present in the air CO2N2O2etc. in the superconducting core 2. Moreover, it can be inferred CO2N2O2and so, the present inside stranded wire 1.

After that, as shown in figure 2 and 8, a stranded wire 1 is subjected to the second rolling stage S12). The second rolling is carried out by compression, for example, 0-20%.

After that, as shown is as 2 and 5, stranded wire 1 is kept on the holder 22 in the chamber 20 in an atmosphere of reduced pressure, for example, for at least 72 hours (stage S13). Inside the chamber 20 there is an atmosphere, for example, gaseous nitrogen, gaseous argon or dry air. Because stranded wire 1 is kept in an atmosphere of reduced pressure, can be suppressed from entering present in the air CO2N2O2etc. in the superconducting core 2. Moreover, it can be eaten WITH2N2O2and so, the present inside stranded wire 1.

After that, a stranded wire 1 is heated to a temperature of, for example, 800-850°C in an atmosphere with high blood pressure and maintained at this temperature for 10-150 hours, and thus stranded wire 1 is subjected to a second sintering stage (stage S14). It should be noted that the second sintering can be performed at atmospheric pressure, and not in the atmosphere under high pressure. Although the superconducting wire according to this variant embodiment receives as described above, can be performed more rolling and sintering after the second sintering, as described above, the second rolling and the second sintering can be omitted.

A method of manufacturing a superconducting wire according to this variant embodiment consists in SEB the phase lug wire 1A, formed by cladding powder 2A source material for the superconductor-metal (stage S3), the stage of the first rolling (stage S8) stranded wire 1C stage after drawing (stage S3) and the first stage of sintering (stage S10) stranded wire 1 after the first stage of the rolling (stage S8). The method additionally includes the stage of exposure clad wire 1b, stranded wire 1C or stranded wire 1 in the atmosphere of reduced pressure in the at least one gap between the stage lug (stage S3) and the stage of the first rolling (stage S8) and the gap between the stage of the first rolling (stage S8) and the first stage of sintering (stage S10) (stage S4, step S7, step S9).

A method of manufacturing a superconducting wire according to this variant embodiment includes a stage lug wire 1A formed by cladding powder 2A source material for the superconductor-metal (stage S3), the stage of the first rolling (stage S8) stranded wire 1C stage after drawing (stage S3), the first stage of sintering (stage S10) stranded wire 1 after the first stage of the rolling (stage S8), the second stage rolling (stage S12) stranded wire 1 again after the first stage of sintering (stage S10) and the second stage of sintering (stage S14) stranded wire 1 again after stage the second use of the TCI (stage S12). The method additionally includes the stage of exposure clad wire 1b, stranded wire 1C or stranded wire 1 in the atmosphere of reduced pressure in the at least one gap between the stage lug (stage S3) and the stage of the first rolling (stage S8), the gap between the stage of the first rolling (stage S8) and the first stage of sintering (stage S10), the gap between the first stage of sintering (stage S10) and the second stage rolling (stage S12) and the gap between the stage of the second rolling (stage S12) and the second stage of sintering (stage S14) (stage S14, step S7, step S9, step S11, step S13).

In accordance with the method of manufacturing according to this variant embodiment can be suppressed from entering present in the air CO2N2O, and o2in powder 2A of the source material. Moreover, since the clad wire 1b, stranded wire 1C or stranded wire 1 is kept in an atmosphere of reduced pressure, the residues contained within the clad wire 1b, stranded wire 1C or stranded wire 1, such as CO2N2O2and so on, is displayed through both leaf plot clad wire 1b, stranded wire 1C or stranded wire 1 or through the shell 3 covering the superconductor. As a result, heterophase during sintering b the children be formed with a smaller probability, and the wire will have a uniform thickness, so that may be obtained superconducting wire having high and uniform operating characteristics.

In the method of manufacturing a superconducting wire according to this variant embodiment of the phase extracts (stage S9) is performed in the interval between the stage of the first rolling (stage S8) and the first stage of sintering (stage S10). Thus, can be obtained superconducting wire having a higher and more uniform performance.

In the method of manufacturing a superconducting wire according to this variant embodiment atmosphere of reduced pressure has a pressure of not more than 0.01 MPa. Thus, can be further suppressed from entering present in the air CO2N2O, and o2in the superconducting core 2.

In the method of manufacturing a superconducting wire according to this variant embodiment of the phase extracts (stage S4, step S7, step S9, step S11, step S13) is performed for at least 72 hours. Thus, to sufficiently remove the remains contained inside the clad wire 1b, stranded wire 1C or stranded wire 1.

In the method of manufacturing a superconducting wire according to this variant embodiment of a stranded wire 1 is maintained at a temperature of at least 80°being extracts (stud who I S4, stage S7, step S9, step S11, step S13). This promotes evaporation residues contained within the clad wire 1b, stranded wire 1C or stranded wire 1, and thus can be obtained superconducting wire having high and uniform operating characteristics.

In the method of manufacturing a superconducting wire according to this variant embodiment of the phase extracts (stage S4, step S7, step S9, step S11, step S13) is performed in an atmosphere of gaseous nitrogen, gaseous argon or dry air.

This can prevent impurities such as CO2N2O2and so, in the powder source material during the stage of exposure.

Although this variant embodiment has been described for the case where the shutter speed in vacuum (stage S4, 7, 9, 11, 13) is performed in each interval, the present invention is not limited to this case, and it would be sufficient to perform any one of these five stages of aging in vacuum (stage S4, step S7, step S9, step S11, step S13).

Moreover, although this variant embodiment has been described for the case where the shutter speed in vacuum (stage S11), the second rolling stage S12), the shutter speed in vacuum (stage S13) and the second sintering stage (stage S14) is executed after the first sintering (stage S10), these stages may be omitted, and the manufacturing superconducting wire mod is et to be completed after the first sintering (stage S10).

In addition, although in this variant embodiment the explanation was given with reference to the method of manufacturing a stranded oxide superconducting wire with bismuth, having a Bi2223 phase, the present invention is also applicable to the method of manufacturing an oxide superconducting wire having a composition different from the composition with bismuth, such as, for example, the composition of yttrium type. In addition, the present invention is also applicable to the method of manufacturing a single-core superconducting wire.

Examples

Below will be described examples of the present invention.

The first example

In this example investigated the effects of aging in vacuum (stage S9) after the first rolling (stage S8). In particular, there was obtained a powder 2A of the source material, having a Bi2223 phase (stage S1), and thereafter the powder 2A source material was filled in the tube 3A (stage S2) with the formation of the wire 1A. Then wire 1A was subjected to drawing with the formation of the clad wire 1b (stage S3), and, without exposing stage aging in a vacuum, many clad wire 1b were collected in a bundle and inserted into the tube 3b (stage S5) with the formation of stranded wire 1C. Then stranded wire 1C was subjected to drawing (stage S6) and, without exposing stage aging in a vacuum, performed the first rolling stranded wire 1C (one hundred the Oia S8) to obtain the band-shaped stranded wire 1. Then stranded wire 1C samples 2-4 kept at room temperature for one month under the pressure of the atmosphere, maintaining a stranded wire 1, respectively, at atmospheric pressure of 0.01 MPa 0.001 MPa (stage S9). Stranded wire 1 sample 1 was kept at room temperature for one day under atmospheric pressure. Then on stranded wire 1 performed the first sintering (stage S10) and, without the stage of aging in vacuum was performed the second rolling stage S12). Then, without stage aging in a vacuum, did the second sintering stranded wire 1 (stage S14) obtaining two pieces of superconducting wires 1, each of which had a length of 400 meters, These two received a piece of superconducting wire 1 were named respectively by party a and party C. After that, each of party a and party was divided into five pieces for the measurement of critical current (a) and thickness (mm) of each piece of superconducting wire 1. Table 1 shows the measurement results. In table 1, sample 1 is a superconducting wire, sustained at atmospheric pressure for one day, and sample 2 is a superconducting wire, sustained at atmospheric pressure for one month. Sample 3 is a superconducting wire having a period of one month is in the atmosphere of reduced pressure of 0.01 MPa, and the sample 4 is a superconducting wire, aged for one month in an atmosphere of reduced pressure of 0.001 MPa.

Table 1
No. sampleThe critical current (A)The thickness of the superconducting wire (mm)
1Party80-900,25 ± 0,01
Party80-900,25 ± 0,01
2Party60-700,27 ± 0,02
Party60-700,27 ± 0,03
3Party80-900,24 ± 0,01
Party80-900,24 ± 0,01
4Party80-900,24 ± 0,01
Party80-900,24 ± 0,01

As shown in table 1, in sample 1, the critical current was 80 to 90 A, and the thickness was 0.25 mm ± 0.01 mm in both parties a and B. In the case of sample 2, the critical current was 60 to 70 And in both parties a and b, and the thickness of the party And the sample 2 was 0.27 mm ± 0.02 m is, while the thickness of party B in the sample 2 was 0.27 mm ± 0,03 mm In the case of sample 3 the value of the critical current ranged from 80 to 90 A, and the thickness was 0.24 mm ± 0.01 mm in both parties a and B. In the case of sample 4, the magnitude of the critical current ranged from 80 to 90 A, and the thickness was 0.24 mm ± 0.01 mm in both parties a and B.

Based on the above results, it was found that in any of the samples 1-4 magnitude of the critical current in each lot has a deviation of about 10 A. Therefore, it was found that variations occur with less probability for each of the working characteristics of the obtained superconducting wire with a shutter speed of this superconducting wire between the first roll and the first sintering under steady-state conditions. Moreover, since the magnitude of the critical current in samples 3 and 4 are higher than in sample 2, it was found that the superconducting wire with high performance can be obtained by holding the wire between the first roll and the first sintering in an atmosphere of reduced pressure. Moreover, since the samples 3 and 4 have smaller thickness than the thickness in samples 1 and 2, and they have smaller variations in thickness, it was found that the extract of the wire between the first roll and the first sintering in an atmosphere of reduced pressure PR is sutstvie in the air CO 2N2O2and so less likely to get into the wire, and their remains contained inside the wire are removed.

The second example

In this example, studied the effect on the wire period of time in vacuum (stage S9) after the first rolling (stage S8). In particular, superconducting wire 1 was obtained by a method almost identical to the method described in the first example. Stranded wire 1C of the sample 5 was first subjected to the first rolling (stage S8), and then kept at room temperature for one day under atmospheric pressure (stage S9). Stranded wire 1C samples 6-9 first subjected to the first rolling stage S8), and then kept at room temperature in an atmosphere with a pressure of 0.01 MPa, respectively, one day, three days, ten days and one month (stage S9). Were measured thickness (mm) of the respective samples of the superconducting wire 1. Table 2 shows the results of measurements. In table 2, the sample 6 is a superconducting wire having an atmosphere with a pressure of 0.01 MPa in one day, the sample 7 is a superconducting wire having an atmosphere with a pressure of 0.01 MPa for three days, the sample 8 is a superconducting wire having an atmosphere with a pressure of 0.01 MPa for ten days, and the sample 9 is the superconducting wire, aged in an atmosphere with a pressure of 0.01 MPa for one month.

Table 2
No. sampleThe thickness of the superconducting wire (mm)
5Party0,25 ± 0,01
Party0,25 ± 0,01
6Party0,25 ± 0,01
Party0,25 ± 0,01
7Party0,24 ± 0,01
Party0,24 ± 0,01
8Party0,24 ± 0,01
Party0,24 ± 0,01
9Party0,24 ± 0,01
Party0,24 ± 0,01

As shown in table 2, in sample 5, the thickness was 0.25 mm ± 0.01 mm in both parties a and B. In the case of sample 6, the thickness was 0.25 mm ± 0.01 mm in both parties a and B. In the case of sample 7, the thickness was 0.24 mm ± 0.01 mm in both parties a and B. In the case of sample 8, the thickness was 0.24 mm ± 0.01 mm in both parties a and B. In the case of sample 9 thickness was 0.24 mm ± 0.01 mm both parties a and B.

the C obtained above results, given that the samples 7-9 have smaller thickness than the thickness of the samples 5 and 6, it was found that exposure of the wire between the first roll and the first sintering in an atmosphere of reduced pressure for at least three days (72 hours) allows sufficiently to bring the remains contained inside the wire.

The third example

In this example, studied the effect on the wire temperature exposure when the shutter speed in vacuum (stage S9) after the first rolling (stage S8). In particular, superconducting wire 1 was obtained by a method almost identical to the method described in the first example. Stranded wire 1C samples 10-13 first subjected to the first rolling (stage S8), and then kept in an atmosphere at a pressure of 0.01 MPa for seven days, respectively, at room temperature, 50°S, 80°300°With (stage S9). Were measured critical current (A) of the respective samples. Table 3 shows the results of measurements. In table 3, the sample 10 is a superconducting wire aged at room temperature, the sample 11 is a superconducting wire aged at a temperature of 50°S, sample 12 is a superconducting wire aged at a temperature of 80°S, and the sample 13 is a superconducting wire aged at a temperature of 300°C.

Table 3
No. sampleThe critical current (A)
10Party80-90
Party80-90
11Party80-90
Party80-90
12Party85-90
Party85-90
13Party85-90
Party85-90

As shown in table 3, in the case of sample 10, the magnitude of the critical current ranged from 80 to 90 And in both parties a and B. In the case of sample 11 the critical current ranged from 80 to 90 And in both parties a and B. In the case of sample 12, the magnitude of the critical current ranged from 85 to 90 And in both parties a and B. In the case of sample 13 the critical current ranged from 85 to 90 And in both parties a and B.

From the above results, given that the samples 12 and 13 have a higher value of the critical current than the magnitude of the critical current in samples 10 and 11, and they have smaller deviations in the values of the critical current, it was found that the superconducting wire with a higher and more homogeneous workers : what IKI can be obtained by holding the wire between the first roll and the first sintering in an atmosphere of reduced pressure at a temperature of at least 80° C.

It should be clear that the disclosed here a variant of the embodiment and examples of the present invention shown in all respects only as illustrative and should not be construed as limitations. Scope of the present invention is defined not by the above description and the attached claims, and it is intended to cover all modifications within the entity and the amount equivalent to the essence and scope of the claims.

1. A method of manufacturing a superconducting wire (1), comprising the stage of:

lug wire (1A)formed by the cladding powder (2A) of the source material for the superconductor-metal (3A) (S3);

rolling mentioned wire (1A) after the stage of drawing (S3) (S8)

and

sintering the above-mentioned wire (1A) after the stage of rolling (S8) (S10);

the method additionally includes the stage shutter-mentioned wire (1A) in the atmosphere of reduced pressure in the at least one gap between the stage of drawing (S3) and the above-mentioned stage rolling (S8) and the gap between the stage of rolling (S8) and the above-mentioned stage of sintering (S10) (S4, S7, S9).

2. A method of manufacturing a superconducting wire (1) according to claim 1, in which

mentioned atmosphere of reduced pressure is pressure is not more than 0.01 MPa.

3. A method of manufacturing a superconducting wire (1) according to claim 1, in which stage shutter speed (S4, S7, S9) are performed for at least 72 hours

4. A method of manufacturing a superconducting wire (1) according to claim 1, in which the above mentioned stage shutter speed (S4, S7, S9) mentioned wire (1A) is maintained at a temperature of at least 80°C.

5. A method of manufacturing a superconducting wire (1) according to claim 1, in which the mentioned stage shutter speed (S4, S7, S9) is performed in an atmosphere of gaseous nitrogen, gaseous argon or dry air.

6. A method of manufacturing a superconducting wire (1), comprising the stage of:

lug wire (1a)formed by the cladding powder (2A) of the source material for the superconductor-metal (3A) (S3);

rolling mentioned wire (1a) n times (n is an integer not less than 2) (S8, S12) and sintering the above-mentioned wire (1A) n times (S10, S14);

at this stage the first rolling (S8) at the above-mentioned stage rolling mentioned wire (1A) n (S8, S12) is performed after the stage of drawing (S3),

the first stage of sintering (S10) at the said stage of sintering the above-mentioned wire (1a) n times (S10, S14) is performed after the first stage of rolling (S8),

stage k-th (k is an integer satisfying n≥k≥2) rolling on the aforementioned stage rolling mentioned wire (1a) n (S8, S12) is executed after a hundred is AI (k-1)-th sintering mentioned on stage sintering wire (1a) n times,

stage k-th sintering at the said stage of sintering the above-mentioned wire (1a) n times (S10, S14) is executed after stage k-th rolling on said stage rolling mentioned wire (1a) n times, and

the method additionally includes the stage shutter-mentioned wire (1A) in the atmosphere of reduced pressure in the at least one gap between the stage of drawing (S3) and the above-mentioned stage of the first rolling (S8), the gap between the stage of the first rolling (S8) and the above-mentioned first stage of sintering (S10), the gap between the said stage (k-1)-th sintering and the above-mentioned stage of the k-th rolling mill and between the said stage of the k-th rolling and the said stage of the k-th sintering (S4, S7, S9, S11, S13).

7. A method of manufacturing a superconducting wire (1) according to claim 6, in which the mentioned stage shutter speed (S9) is performed in the interval between the first stage rolling (S8) and the above-mentioned first stage of sintering (S10).

8. A method of manufacturing a superconducting wire (1) according to claim 6, in which said atmosphere of reduced pressure has a pressure of not more than 0.01 MPa.

9. A method of manufacturing a superconducting wire (1) according to claim 6, in which the mentioned stage shutter speed (S4, S7, S9, S11, S13) are performed for at least 72 hours

10. A method of manufacturing a superconducting wire (1) according to claim 6, in which the above mentioned stage : is Riki (S4, S7, S9, S11, S13) mentioned wire (1A) is maintained at a temperature of at least 80°C.

11. A method of manufacturing a superconducting wire (1) according to claim 6, in which the mentioned stage shutter speed (S4, S7, S9, S11, S13) is performed in an atmosphere of gaseous nitrogen, gaseous argon or dry air.



 

Same patents:

FIELD: cable industry; production of polymeric items.

SUBSTANCE: proposed device has frequency changer, high-voltage transformer, gas-discharge reactor, photoelectronic multiplier with display unit, polarized degree-of-stitch and its uniformity indicator, and reactor gas mixture pressure build-up and maintenance unit. Sectionalized gas reactor of type depending on cable thickness is used, each reactor section having variable-diameter quartz glass tube; these tubes are installed in tandem and cable conductor covered with insulation applied by extrusion is passed through them. Compressed inert gas (nitrogen or argon) is supplied to tube of each reactor from gas cylinder at pressure of 10 at. Attached to external wall of quartz tube are conductive metal electrodes and industrial- or high-frequency (50, 150, or 300 Hz) AC voltage of 10 to 70 kV is applied across them. Metal current-carrying conductor of cable functions as gas-reactor central grounded electrode.

EFFECT: facilitated procedure and enhanced safety of stitching cable polyethylene and polypropylene using industrial method.

1 cl, 3 dwg

FIELD: electric cable manufacture.

SUBSTANCE: proposed method includes following procedures: (a) conductor feeding at predetermined feed rate; (b) extrusion of thermoplastic insulating layer in position radially external with respect to conductor; (c) cooling down of foamed insulating layer; (d) production of circumferentially closed metal shield about mentioned extruded insulating layer. Novelty is that procedures are conducted uninterruptedly, that is, time passed from end of cooling procedure to initiation of shield formation is inversely proportional to conductor feed rate.

EFFECT: reduced manufacturing time, enhanced mechanical strength of cable.

19 cl, 5 dwg, 2 tbl, 1 ex

FIELD: electric cable manufacture.

SUBSTANCE: proposed method includes following steps: (a) feeding conductor at predetermined feed rate; (b) extruding thermoplastic insulating layer in radial direction on external side of conductor; (c) cooling down insulating layer obtained by extrusion to temperature not over 70 °C; (d) forming metal screen closed on circumference around mentioned insulating layer obtained by extrusion. Procedures are run continuously, that is, period between cooling-down step and initiation of screen formation is inversely proportional to conductor feed rate.

EFFECT: facilitated procedure.

19 cl, 10 dwg

FIELD: superconducting wire manufacture.

SUBSTANCE: proposed method for producing superconducting wire includes production of wire material in the form of source powdered metal-covered and oxide-coated superconducting material and heat treatment of wire material obtained in the process in high-pressure environment with total pressure maintained at 1 MPa or higher and below 50 MPa in the course of heat treatment; pressure rise is started with temperature at which 0.2% conventional yield point of metal becomes lower than total pressure in the course of heat treatment. Such procedure makes it possible to eliminate voids between oxide-coated superconducting material crystals and bulging of oxide-coated superconducting wire material, as well as to easily control oxygen partial pressure during heat treatment.

EFFECT: enhanced critical current density in wire material obtained.

22 cl, 27 dwg, 3 tbl

FIELD: cable engineering.

SUBSTANCE: proposed coaxial cable is provided with specially prepared layer of pre-coating which facilitates its removal when cable end is stripped to receive connector. Cable has internal conductor, foamed polyolefin insulating layer, external conductor covering mentioned insulating layer, and pre-coating disposed between internal conductor and insulating layer. Pre-coating layer forms first internal-conductor bonding interface and second insulating-layer bonding interface; ratio of adhesive force on axial shift of first bond A to adhesive force on second axial shift of second bond B is below 1; ratio of adhesive force on axial shift of bond A formed by pre-coating layer between internal conductor and insulating layer to adhesive force on rotational shift of this bond is 5 or higher.

EFFECT: improved electrical characteristics of cable, enhanced reliability of line using this cable.

13 cl, 5 dwg, 1 tbl

FIELD: electrical engineering including cable engineering; midget control cables for wire communication lines of small-size missiles and their manufacturing process.

SUBSTANCE: proposed midget control cable has two electrically insulated enameled copper conductors (current-carrying conductors), one strengthening complex thread of cross securing lea winding of three polyamide threads forming thread assembly, as well as seven strengthening complex threads placed on top of cross securing winding in parallel with copper conductors, and secondary securing winding of one complex strengthening thread; thread assembly is impregnated with water-repelling liquid. Proposed method for manufacturing midget control cable includes manufacture of thread assembly followed by finishing midget control cable for which purpose seven strengthening complex threads are arranged in parallel with thread assembly whereupon finished midget control wire is wound on take-in reel.

EFFECT: improved electrical and mechanical characteristics, ability of using cable immersed in water including sea water.

2 cl, 2 dwg

FIELD: electrical engineering including cable engineering; midget control cables for wire communication lines of small-size missiles and their manufacturing process.

SUBSTANCE: proposed midget control cable has two electrically insulated enameled copper conductors (current-carrying conductors), one strengthening complex thread of cross lea securing winding of three polyamide threads forming thread assembly, as well as four strengthening complex threads placed on top of cross securing winding in parallel with copper conductors, two-layer lea winding of two polyamide threads wound in opposite directions, and one complex thread. Proposed method for manufacturing midget control cable includes manufacture of thread assembly followed by finishing midget control cable for which purpose four strengthening complex threads are arranged in parallel with thread assembly and two-layer winding is placed overall.

EFFECT: improved electrical and mechanical characteristics, ability of using cable immersed in water including sea water.

2 cl, 3 dwg

FIELD: electrical engineering.

SUBSTANCE: proposed superconducting device has superconducting oxide wire made of superconducting oxide material whose post-sintering density is 93% and more, best 95% and more, or most preferably 99% or more, which is attained by heat treatment of wire in enhanced pressure environment of at least 1 MPa and below 50 MPa. Heat treatment of wire at enhanced pressure prevents formation of gaps and bubbles. Stable superconducting oxide phase of Bi2223 is formed in the process.

EFFECT: enhanced critical current density of superconducting device and superconducting cable.

6 cl, 27 dwg, 4 tbl, 6 ex

FIELD: electrical engineering; using silanol cross-linked polyethylene covered wires or cables.

SUBSTANCE: proposed method includes covering of cable or wire conductor with silanol cross-linked polyethylene insulation followed by cooling down wires or cables and placing them in horizontal branches into water-filled basket. After that either current is passed through cable or wire thereby heating it to temperature not over maximal admissible value ensuring insulation resistance to thermal deformation and exposing it to this temperature for period required for silanol cross-linking of polyethylene, or basket is placed in heated tank filled with water, steam, or steam-water mixture, and held in this tank at mentioned temperature for time required for polyethylene cross-linking, or water is drained from basket and then the latter is placed in heated tank filled with water, steam, or steam-water mixture and held in this tank at mentioned temperature for time required to ensure silanol cross-linking of polyethylene.

EFFECT: enhanced quality of insulation, reduced cost, time, and heat energy requirement.

4 cl

FIELD: electrical and power engineering; sealed entries for passing conductors into pressurized premises or locations.

SUBSTANCE: proposed sealed cable entry designed to pass Lead-in cables into pressurized premises or locations has cylindrical metal body with flanges attached to its butt-ends by way of electric-arc welding for passing through them mineral material covered and insulator-terminated cables; insulators are made of oxide ceramics with titanium evaporated on them at solder points for better wettability of AgCu and ceramic surface. Proposed manufacturing process is characterized in that insulators are joined to metal sheath of mineral insulation covered cables by way of active soldering with AgCuTi system in vacuum furnace.

EFFECT: enhanced quality of soldered joints, simplified design of sealed modules, reduced number of process operations.

2 cl, 1 dwg

FIELD: electrical engineering; automobile and ship building, mechanical engineering, construction , oil extraction, and oil refining industries.

SUBSTANCE: proposed electric drive has stranded copper conductor with strand sectional area of 1.0 - 50 mm3 and rubber sheath , 0.4 - 7.0 mm thick, made of rubber mixture whose matrix is polymeric mixture of high-molecular polymethyl vinyl-siloxane and low-molecular polymethyl vinyl-siloxane rubber of mole mass of 20 -70 thousands in combination with silica powder, quartz, anti-texturing agent in the form of αω-dihydroxide methylsiloxane and organic peroxide. Rubber mixture is applied by extrusion at speed of 0.2 - 2 m/s and cured under radiation-chemical curing conditions with aid of cobalt gun incorporating γ-radiation source at dose rate of 2.5 - 20 megarad. and/or by thermal curing. Electrical conductor produced in the process is capable of fire self-suppression and is suited to operate at -60 to +300 °C.

EFFECT: enhanced fire, crack, oil, and gasoline resistance, improved electrical and physical characteristics.

3 cl, 1 tbl

FIELD: cable engineering; plastic-covered sector cables.

SUBSTANCE: proposed extrusion head that provides for regulating insulation thickness over perimeter of sector cable cores has body, mandrel holder, mandrel with cylindrical part, die, mandrel evacuation device, and device for positioning conducting core in mandrel; two cuts symmetrical relative to vertical axis of mandrel are made on external surface of its cylindrical part; these cuts are disposed so that fixed radiant position of sector in mandrel is ensured and its rays originate from geometric center of mandrel and cross points limiting left- and right-hand rounding of sector; angle between symmetry axes of cuts is not over 180 deg.; angle of cuts to generating lines of cylinder is minimum 1 deg.

EFFECT: reduced material input of cable.

1 cl, 3 dwg, 1 tbl

FIELD: electrical engineering; drying cable insulation in servicing communication lines.

SUBSTANCE: proposed electroosmotic method for drying paper insulation of cable involves setting-up of electric field; in the process cable conductors are connected to positive pole of current supply, metal electrodes whose quantity depends on that of cable conductors are inserted in paper insulation at open end of cable and connected to negative pole of power supply; damp cable section is cut off. Used as metal electrodes are aluminum or copper strips deepened through 2 m. Voltage of 500 - 2500 V is applied for 6 - 8 h.

EFFECT: enhanced cable saving due to reduced size of cut-off ends.

1 cl

FIELD: electrical engineering.

SUBSTANCE: invention relates to manufacture of electroconductive materials by way of applying electroconductive coating, impregnated-paper insulation, and electroconductive threads of power cables onto paper base. In particular, material consists of natural paper base and electroconductive layer, whose thickness constitutes 0.03-0.14 that of insulation layer placed on paper and composed of aqueous suspension of carbon black (6-10%) and polyvinyl alcohol (1.0-4.0%) together with additives of acrylic acid ester/methacrylic acid ester copolymer (7-12%) and oxyethylated (with at least 7 ethylene oxide groups) alkylphenol or sodium polyacrylate (0.1-0.5%).

EFFECT: improved workability, electrical conductivity, strength, elasticity, heat resistance, moisture resistance, and resistance to splitting within cable.

3 tbl

Electric cable // 2256969

FIELD: electrical engineering; electric cables for signaling, control, and data transfer and processing systems.

SUBSTANCE: cable has at least one pair of insulated and stranded current-carrying conductors and cable sheath. Insulating material is either halogen-containing polymer (polyvinyl chloride), or halogen-free polyolefin base material (polyethylene), or its copolymer. Insulation thickness is chosen from equation strand pitch is found from equation h = 25(2Δ + d), where d is conductor diameter; εr is relative dielectric constant of insulating material. With diameter of cable current-carrying conductors being enlarged, capacitance of cable pair was reduced (other characteristics being retained at desired level.

EFFECT: enhanced capacitance of working load on cable pair.

1 cl, 4 dwg, 1 tbl

FIELD: electrical engineering; producing long conductors around superconducting compounds.

SUBSTANCE: proposed method includes formation of single-core billet by filling silver sheath with bismuth ceramic powder; deformation of this single-core billet to desired size by no-heating drawing at deformation degree per pass of 0.5 - 20%; cutting of deformed billet into measured parts; assembly of single-core billet by disposing desired quantity of measured parts of deformed single-core billet in silver sheath of multicore billet; extrusion of multicore billet at temperature ranging between 100 and 200 °C and at drawing coefficient of 4 to 30; air rolling without heating at deformation degree per pass of 1 - 50%; thermomechanical treatment including several heat-treatment stages at temperature of 830 - 860 °C for time sufficient to obtain phase of desired composition and structure in ceramic core with intermediate deformations between heat-treatment stages at deformation degree per pass of 5 - 30 %.

EFFECT: enhanced critical current density due to sequential packing of ceramic core; facilitated manufacture.

1 cl, 1 ex

FIELD: controlling electric cable sheath capacitive reactance.

SUBSTANCE: proposed method for controlling capacitive reactance of tubular sheath formed by means of extrusion of insulating compound on electric cable in extrusion head includes introduction of foaming agent in insulating compound so as to enhance capacitive reactance of tubular insulating sheath; prior to do so, definite amount of foaming agent is used so as to obtain predetermined capacitive reactance for tubular insulating sheath and in order to ensure precision control of capacitive reactance of tubular insulating sheath, gas pressure is applied to at least external surface area of insulating compound extruded by extrusion head, gas pressure being varied so as to control capacitive reactance value of tubular insulating sheath.

EFFECT: enhanced precision of controlling capacitive reactance of electric-cable sheath.

9 cl, 3 dwg

FIELD: electrical engineering; cable filler compositions.

SUBSTANCE: proposed PVC base composition designed for filling conductor-to-conductor space of electric cables by extrusion has following ingredients, parts by weight: divinyl-styrene thermal elastomer, 100; high-pressure polyethylene, 40 - 60; mineral oil, 80 - 95; chalk or kaolin, or aluminum hydroxide, 100 - 50.

EFFECT: enhanced fluidity index and frost resistance; ability of retaining cable flexibility at sub-zero temperatures.

1 cl

FIELD: multiple twin cables for communications in local network.

SUBSTANCE: proposed multiple twin cable designed to prevent vapor transfer when immersed in petroleum oil has internal and external sheaths that cover insulated signal-transferring conductors and are made in the form of helical structure. Core filler fills up core and spaces between signal transferring conductors. Core filler and internal sheath are made of vapor-tight material and fixed to insulated conductors so that they fill up all grooves and slots around signal transferring conductors. External gas-tight sheath can be provided to make it possible to immerse cable in petroleum oil for long time intervals without impairing its functional capabilities.

EFFECT: ability of preventing vapor transfer lengthwise of cable.

26 cl, 4 dwg

FIELD: cable line engineering; solving problem of cable line immunity to external electromagnetic noise.

SUBSTANCE: proposed method for noise suppression in cable lines includes electrical interconnection of two cable conductors on one end directly or through resistors , addition of signals from their other ends, and at least partial disposition, principally symmetrical, of figures formed by one pair of conductors including conductors proper and space between them in space between other pair of conductors. Circuits of interconnected conductors are balanced, for instance, with respect to their resistance. Cable has two pairs of conductors, each pair is directly or mediately parallel-connected and figure formed by one pair of conductors that includes conductors proper and space between them is at least partially disposed in space between other pair of conductors, principally symmetrically. Cable manufacturing process includes insulation of conductors and their relative fastening in space; each pair of four conductors is directly or mediately parallel-connected and disposed in space so that figure formed by one pair of conductors incorporating conductors proper and space between them is at least partially disposed in space between other pair of conductors, principally symmetrically.

EFFECT: reduced fraction of electromagnetic noise in signal transferred over cable lines.

6 cl, 9 dwg

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