Superconducting wire, superconducting stranded wire with use thereof and method to manufacture thereof

FIELD: chemistry; electric wire.

SUBSTANCE: material in the form of oxide superconducting wire, which comprises oxide superconducting part and metal coating thereon, distinguishing itself by the fact that the above metal coating material during stress-strain relationship test features relative rupture strain of 30% or more.

EFFECT: material in the form of superconducting wire features high critical current density and is less susceptible to vertical cracking or breaking during manufacture.

14 cl, 3 dwg, 1 tbl, 10 ex

 

The technical field

The present invention relates to a superconducting wire. In particular, the present invention relates to a superconducting wire containing oxide superconductor and a metal sheath. The present invention relates to a superconducting multi-core wire, which includes a number of such superconducting wires and the second metal shell.

In addition, the present invention relates to a method of manufacturing a superconducting wire. The present invention relates also to a method of manufacturing the superconducting stranded wires.

The level of technology

As the oxide high-temperature superconducting wires were traditionally developed stranded wire based on bismuth. As a method of manufacturing a stranded wire-based bismuth-known technique of forming an oxide superconductor containing, for example, the phase of (BiPb)2Sr2Ca2Cu3Ox(phase Bi-2223), in the form of a long ribbon-like wire by way of the "powder in tube". In this way, for example, a metal tube initially fill the starting powder of the superconducting phase, and then pull in the form of clad wire. Many of these clad wires again inserted into a metal tube and you agimat in a stranded wire. Stranded wire rolled into a ribbon wire, in which the metal shell accommodates multiple superconducting lived.

In this way the tape wire is then subjected to primary heat treatment to obtain the target superconducting phase. Then tape the wire again rolled for passing the secondary heat treatment, so that the crystallites in the superconducting phase are associated with each other. Although the pressure treatment and a heat treatment is performed twice, each of them can only be run once.

Since the oxide superconductor based on bismuth phase Bi-2223 as the most famous example, is a ceramics and tends to be brittle and less flexible, it is usually planiruet metal shell. However, the metal of a particular type, used for metal shell, as is known, a negative effect on the superconducting characteristics of the oxide superconductor based on bismuth. Therefore, to obtain a metal shell often use silver, which is known to have no negative impact on them.

When compared with the superconducting wires are identical in cross-sectional area and a critical current density of the oxide superconductor wire with a larger share (in cross section) of the oxide superconducting phase characterizes the large value of the critical current. Therefore, from the point of view of the characteristics of the critical current, it is preferable to produce a superconducting wire with the largest possible share of the oxide superconductor. However, in the manufacture of superconducting wire increases less durable fragile part that tends to cause its longitudinal cracking and breaking during processing. If you continue to process the portion of the superconducting wire with longitudinal cracks, the interior of this part subject to formation of inhomogeneities, which significantly reduces the critical current density. Therefore, the fabrication of superconducting wires with optimal characteristics becomes difficult.

To ensure the possibility of manufacturing a superconducting wire with optimal characteristics we developed a number of technologies related to its manufacturing process. For example, disclosed a method of manufacturing a superconducting wire, comprising the steps of filling a metal tube, the source powder of the superconducting phase and the processing of metal tubing pressure at least once and its heat treatment at least once to receive the wires, and conducting heat treatment at a low oxygen content so that the wire is heated at a temperature lower than the temperature you upomanutoi heat treatment in oxygen-depleted atmosphere in comparison with air (see patent document 1). This method can be used to increase the critical current of the superconducting wire is relatively well-known traditional method.

However, when manufacturing a superconducting wire with a large share of the oxide superconductor increases less durable fragile part. Therefore, even in the case of this method, it is difficult to eliminate the tendency to longitudinal cracking and breakage during processing.

Disclosed is also a method of manufacturing a superconducting wire, comprising the steps of filling a metal tube, the source powder of a superconducting phase; pulling this metal tube clad wire; linking many clad wires to re-insert them in a metal tube so that the clad wires are placed in the shape of a polygon and extrude this metal tube in a stranded wire; rolled stranded wire ribbon wire, in which a metal sheath holds many superconducting lived. In this way a stranded wire rolled swaging in a diagonal direction or in the direction from one side to the opposite side of the cross section in the shape of a polygon taken planirovanie wires (see patent document 2).

However, in the manufacture of superconducting wire with the largest share of the oxide superconductor less durable fragile part increases. Therefore, even in the case of this method, it is difficult to suppress the tendency to longitudinal cracking and breakage during processing.

Patent document 1: Japanese Laid patent No. 2003-203532

Patent document 2: Japanese Laid patent No. 2003-242847

Disclosure of invention

Problems to be solved by the invention of

In accordance with the above, in the manufacture of superconducting wire with a large share of the oxide superconductor less durable fragile part increases. Therefore, the problem of its longitudinal cracking and tear caused during processing, has not been solved completely.

Therefore, the aim of the present invention is to provide a superconducting wire, the critical current density is high due to the large proportion of an oxide superconductor and which is less susceptible to longitudinal cracking and tearing at the stage of its manufacture.

Another objective of the present invention is to provide a superconducting multi-core wire, the critical current density is high due to the large proportion of an oxide superconductor and which is less susceptible to longitudinal cracking and tearing at the stage of its manufacture.

Another objective of the present invention is to provide a method of manufacturing a superconducting wire, with the Convention can be produced, without causing longitudinal cracking and breaking, the superconducting wire with high critical current density due to the large proportion of the oxide superconductor.

An additional objective of the present invention is to provide a method of manufacturing a superconducting multi-core wire, whereby it is possible to make, without causing longitudinal cracking and rupture, superconducting stranded wire with high critical current density due to the large proportion of the oxide superconductor.

Means for solving these problems

The authors of the present invention has advanced the idea that the study of the mechanical properties of the metal shell, such as, for example, silver tube, which before had not paid attention, it would be useful for the above-mentioned problems, and therefore, creation of a test of the superconducting wire and superconducting stranded wires, with different materials and having different structures, for example, to determine what materials and what the state of the metal shell makes it possible to manufacture, without causing longitudinal cracking and rupture, superconducting wire and superconducting stranded wires with high critical current density due to the large proportion of oxide surpro is ednica.

In accordance with the obtained results, the authors of the present invention found that the aforementioned longitudinal cracking and gaps occur because a large proportion of the oxide superconductor actually reduces the amount of material of the metal shell, which serves as a structural material of the superconducting wire and superconducting stranded wires, resulting in this structural material can no longer withstand the stress and strain caused during processing.

The authors of the present invention discovered that by adjusting the destructive deformation of the material of the metal shell when the test stress strain to hit a certain range it is possible to produce a superconducting wire and superconducting stranded wire with high critical current density due to the large proportion of oxide superconductor without causing longitudinal cracking and rupture. Accordingly, the authors present invention has overcome the aforementioned problems and has achieved the above objectives of the present invention.

In particular, the present invention proposes an oxide superconducting wire containing oxide superconductor and a metal shell covering this oxide superconductor, pricemotion metal shell test stress-strain characterized by destructive deformation in at least 30%.

Destructive deformation is preferably within the range from 30% to 58%, more preferably within the range from 45% to 58%. The proportion of oxide superconductor is preferably within the range from 25% to 70%. The material of the metal shell is preferably characterized by a maximum voltage of at least 180 MPa when tested stress-strain.

Material metal shell preferably contains silver and/or silver alloy. Furthermore, the material of the oxide superconductor preferably contains an oxide superconductor on the basis of bismuth. As a material of the metal shell is particularly preferable to use silver with impurity concentration from 10 am/m to 500 hours/million impurity Concentration is also an indicator (indicator) cracking during processing. Therefore, by adjusting the concentration of impurities in the metal sheath can further reduce the incidence of cracking during processing.

Superconducting stranded wire in accordance with the present invention is a superconducting stranded wire, containing a number of superconducting wires and the second metal shell covering these superconducting wires. Superconducting stranded wire preferably they is no ribbon-like form.

A method of manufacturing a superconducting wire in accordance with the present invention includes the steps are filled metal cylinder made of metal material shell, characterized by a test of the stress-strain destructive deformation within a range from 30% to 58%, the starting powder containing source material of oxide superconductor; and subjecting the metal cylinder filled with original powder, the pressure treatment at least once and the heat treatment at least once. To reduce cracking during processing, the preferred material of the metal shell is used for manufacturing a superconducting wire is silver with impurity concentration from 10 am/m to 500 hours/million

A method of manufacturing a superconducting multi-core wire in accordance with the present invention includes the steps are filled metal cylinder made of metal material shell, characterized by a test of the stress-strain destructive deformation within a range from 30% to 58%, the starting powder containing source material of oxide superconductor; expose the metal cylinder filled with original powder, the processing pressure is at least once to get the wire; fill a metal cylinder, which should serve as a material of the second metal shell, a lot of these wires; and subjecting the metal cylinder filled with lots of wires, pressure treatment at least once and the heat treatment at least once to get the superconducting stranded wires. In this way, the preferred material of the metal shell is silver with impurity concentration from 10 to 500 hours/million

The effects of the invention

As described below, the superconducting wire in accordance with the present invention is characterized by excellent critical current density and workability (i.e. the ability to process because it has a high critical current density due to the large proportion of an oxide superconductor and less prone to longitudinal cracking and tearing at the stage of its manufacture due to the destructive deformation of the material of the metal shell, which is within a certain range when tested stress-strain.

Superconducting stranded wire in accordance with the present invention is characterized by excellent critical current density and workability, as it has a high critical current density due to baisogala oxide superconductor and less prone to longitudinal cracking and tearing at the stage of its manufacture due to the destructive deformation of the material of the metal shell, which is within a certain range when tested stress-strain. In addition, a method of manufacturing a superconducting wire in accordance with the present invention makes it possible to produce, without causing longitudinal cracking and breaking, the superconducting wire with high critical current density due to the large proportion of the oxide superconductor.

A method of manufacturing a superconducting multi-core wire in accordance with the present invention makes it possible to produce, without causing longitudinal cracking and rupture, superconducting stranded wire with high critical current density due to the large proportion of the oxide superconductor.

Brief description of drawings

Figure 1 is a block diagram of the process flow showing an example of a method of manufacturing a superconducting wire in accordance with the present invention.

Figure 2 is a block diagram of the process flow showing an example of a method of manufacturing a superconducting multi-core wire in accordance with the present invention.

Figure 3 is a photograph showing how the tests stress-strain on the tube of silver and/or serebrjanoj the alloy, used in examples and comparative examples of the present invention.

Preferred embodiments of the present invention

Below is a detailed description of the present invention based on examples of variants of its implementation.

<Definitions>

In this application under the superconducting wire means a wire containing superconducting phase and the membrane material covering this superconducting phase. Single superconducting wire may contain a single superconducting phase or multiple superconducting phases.

In this application under the superconducting stranded wire refers to wire containing multiple superconducting phases and the membrane material covering these superconducting phase. The sheath material may be a single layer or a multilayer.

In this application, the term "superconducting wire" is intended to encompass a broader concept that includes the superconducting stranded wire. In accordance with the above definition of the superconducting stranded wire can contain multiple superconducting wire and superconducting stranded wire is also seen as a superconducting wire.

<A method of manufacturing a superconducting wire and superconducting stranded Provo is as >

Traditionally, the method of manufacturing a superconducting wire preferably includes the steps of initial preparation of the powder of the oxide superconductor, filling a metal tube this source powder, forming a metal tube filled with the original powder, and carrying out heat treatment of a metal tube filled with original powder and subjected to pressure treatment.

In particular, when the above method of manufacturing a superconducting wire is a method of manufacturing a superconducting multi-core wire, the step of processing by pressure preferably includes the steps of manufacturing a clad wire, the manufacture of stranded wire and rolling stranded wire for the manufacture of the tape wire. Each of the stages of forming and carrying out heat treatment may be performed two or more times.

When the above method of manufacturing a superconducting wire is a method of manufacturing a stranded wire based on bismuth oxide superconductor containing, for example, the phase of (BiPb)2Sr2Ca2Cu3Ox(phase Bi-2223), preferably molded in the form of a long ribbon-like wire by way of the powder in the tube.

In this way use the Yu tube for example, first fill the starting powder of the superconducting phase and then pull in the clad wire. Many of these clad wires connect and again inserted in a metal tube for drawing a stranded wire. Then stranded wire rolled into a ribbon wire, metal shell which holds many superconducting lived.

In this way the tape wire is additionally subjected to primary heat treatment to obtain the target superconducting phase. Then tape the wire again rolled and subjected to secondary heat treatment, so that happened linking crystal grains (crystallites) of the superconducting phase. Although the pressure treatment and a heat treatment is performed twice, each of them can only be run once.

Figure 1 shows a block diagram of a process flow showing an example of a method of manufacturing a superconducting wire in accordance with the present invention. In this way you can also use a method similar to the above-described conventional method of manufacturing a superconducting wire. However, as shown in figure 1, is particularly preferable to use the method of manufacturing a superconducting wire, comprising the steps are filled Qili metal is al, which should serve as a material of the metallic shell and which contains material that Deplete the deformation which when tested stress-strain is within a certain range, the starting powder containing the material of the oxide superconductor (S101), and expose the metal cylinder filled with original powder, the pressure treatment at least once and the heat treatment at least once (S103).

Figure 2 shows the block diagram of the process flow showing an example of a method of manufacturing a superconducting multi-core wire in accordance with the present invention. In this way you can also use a method similar to the above-described conventional method of manufacturing a superconducting stranded wires. However, as shown in figure 2, is particularly preferable to use the method of manufacturing a superconducting stranded wire, comprising the steps are filled metal cylinder, which should serve as a material of the metallic shell and which contains material that Deplete the deformation which when tested stress-strain is within a certain range, the starting powder containing the material of the oxide superconductor (S201), will versaut this metal cylinder, full source powder, the pressure treatment at least once to get the wire (S203), fill a metal cylinder, which should serve as a material of the second metal shell, many of these wires (S205), and subjected to a metal cylinder filled with lots of wires, pressure treatment at least once and the heat treatment at least once to get the superconducting stranded wires (S207).

<The original powder>

As used in the present invention the source of the powder of the oxide superconductor, it is advisable to use the original powder prepared according to this recipe so that you can obtain the superconducting phase, which ultimately can have a critical temperature of at least 77 K. This source powder contains not only the powder, in which a complex oxide are mixed at a given ratio of components, but the powder obtained by sintering this mixed powder and chopped.

When the material, eventually containing oxide superconductor on the basis of bismuth (e.g., on the basis of Bi2223), used as a material of the oxide superconductor according to the present invention, as the starting source powder is preferably mixed use source powder, aderrasi powders of Bi 2O3, PbO, SrCO3, CaCO3and CuO. This mixed source powder is subjected to heat treatment at least once at a temperature of from 700 to 800°C for from 10 to 40 hours in an atmosphere at atmospheric pressure or in a rarefied atmosphere, which may be obtained from the original powder consisting mainly of Bi2212 phase, and not the Bi2223 phase, which can be suitably used as a starting powder of the oxide superconductor in the present invention.

Starting source powder preferably has a specific ratio of components, which satisfies the relation (a+b):c:d:e= 1,7-2,8:1,7-2,5:1,7-2,8:3 in BiaPbbSrcCadCue. Particularly suitable is the ratio of the components, mainly to satisfy the relationship (or Bi (Bi+Pb)):Sr:Ca:Cu = 2:2:2:3. The ratio of Bi:Pb:Sr:Ca:Cu = approximately 1.8:0,3-0,4:approximately 2:approximately 2.2 to approximately 3.0 is especially preferred.

The original powder used in the present invention for filling a metal cylinder, preferably has a maximum grain size in at most a 2.0 μm and the average grain size in at most to 1.0 μm, since the use of such fine powder facilitates obtaining high-temperature oxide superconductor.

<Metal qi is int >

As a material used in the present invention a metal cylinder (metal tube) it is preferable to use at least one metal selected from the group consisting of Ag, Cu, Fe, Ni, Cr, Ti, Mo, W, Pt, Pd, Rh, Ir, Ru and Os, and/or an alloy based on the specified at least one metal. From the point of view of chemical activity with respect to the oxide superconductor and the machinability is particularly preferable to use silver and/or silver alloy.

If the material is a metal cylinder, which should serve as a material of the metal shell used in the manufacture of superconducting wire in accordance with the present invention, the use of the material, destroying the deformation is large enough, can eliminate longitudinal cracking and tears caused during processing, such as rolling. The reason for this is that the material is more destructive deformation has excellent elongation and material with excellent elongation is considered to have a higher flexibility and less prone to longitudinal cracking and tearing.

The material is a metal cylinder used in the present invention preferably is characterized by a destructive deformation in men is our least 30%, and more preferably at least 45%, at test stress strain. Silver/silver alloy is preferably characterized by destructive deformation at most 58%.

From the viewpoint of workability preferred most destructive deformation. However, there is a tendency to reduce the maximum voltage. Therefore destructive deformation is preferably within the above ranges to ensure the workability and performance of the superconductor. When the material of the metal cylinder using silver and/or silver alloy, its breaking strain is approximately 58% at the maximum voltage of 180 MPa, as described below. Therefore, the maximum breaking strain is preferably limited to a value at most 58%.

In addition to higher destructive deformation more appropriate to apply a higher maximum voltage at test stress-strain, because it makes the oxide superconductor is more compact and provides a more uniform shape of its inner section. When the membrane material is characterized by a higher maximum voltage (in particular, the 0.2%conventional yield stress), the oxide surpro is odnako, as well as the sheath material can be applied more force during subsequent processing. The reason for this is that the maximum force applied to the oxide superconductor during processing, is determined by the maximum voltage material metal shell. From the point of view of manufacture more compact oxide superconductor and provide a more uniform internal cross-section, it is advisable to apply any more pressure.

Therefore, the material of the metal cylinder used in the present invention preferably is characterized by a maximum voltage of at least 180 MPa when tested stress-strain, because a larger maximum voltage (maximum voltage) allows you to apply more force to the oxide superconductor during processing of superconducting wire and superconducting stranded wire that allows you to make a superconductor is more compact and provide a more uniform shape of its inner section. In addition, since the metal cylinder made of silver and/or silver alloy, characterized by a maximum voltage of approximately 180 MPa, the use of a metal cylinder, the maximum voltage which is at least 180 MPa, can the provide optimal superconducting wire and superconducting stranded wire.

In a typical metal and/or alloy increased destructive deformation leads to lower maximum voltage. However, to achieve a compact and homogeneous oxide superconductor, best is a higher maximum voltage (in particular, 0,2%conditional yield strength). Therefore, as a material used in the present invention a metal cylinder, it is preferable to use a hard plastic material.

In the case of material a metal cylinder used in the present invention, the use of the material with the above properties is more effective when the proportion of the oxide superconductor in the superconducting wire and a superconducting multi-core wire is at least 30%.

The reason for this is that the material with the above properties is characterized by high elongation and less prone to longitudinal cracking and rupture during processing. If the proportion of the oxide superconductor in the superconducting wire and superconducting stranded wire is reduced, the fraction of the metal shell increases. In this case, although the material is a metal cylinder and has a lower elongation, greater volume allows you to easily handle the superconducting wire and overprovide the second stranded wire. However, if the proportion of the oxide superconductor is equal to or exceeds 30%, it increases the importance of the problem of cracking during processing. Therefore, the more necessary the use of the material in a metal cylinder with high elongation.

<Pressure treatment>

Pressure treatment in the method of manufacturing a superconducting wire and a superconducting multi-core wire in accordance with the present invention includes various kinds of processing by reducing the sectional area. In particular, examples of processing by reducing the sectional area include stretching (drawing), rolling, stamping, crimping, etc.

If the processing pressure in the method of manufacturing a superconducting multi-core wire in accordance with the present invention is performed only once, the processing preferably includes practical stages of processing by reducing the sectional area of a metal cylinder filled with the starting powder to form a clad wire (wire), processing with decreasing cross-sectional area of a metal cylinder into which you have inserted related clad wire to form a stranded wire, and the processing of this stranded wire to ribbon-like form.

Stranded wire formation is anywayt to ribbon-like form, to the crystallites formed in the superconducting stranded wire, were oriented in the same direction. Typically, the current density that can flow through the superconducting stranded wire on the basis of oxides, varies greatly depending on the orientation of the crystallites. Therefore, when the orientation of the crystallites in one direction can be obtained a higher current density.

<Heat treatment>

The heat treatment in the method of manufacturing a superconducting wire and a superconducting multi-core wire in accordance with the present invention is preferably carried out twice or more, and typically perform primary and secondary heat treatment. The primary heat treatment is used, in General, to obtain an oxide superconductor, such as a Bi2223 phase. The secondary heat treatment is intended primarily for strong binding of the crystallites of an oxide superconductor, such as a Bi2223 phase, with each other.

Both primary and secondary heat treatment in the method of manufacturing a superconducting wire and a superconducting multi-core wire in accordance with the present invention is preferably performed at a temperature of at least 815°C, in particular at least 830°C. in Addition, they preferably do p and temperature largely 860° C, in particular at most 850°C.

In particular, is very suitable performing a primary heat treatment at a temperature in the range from 840°C to 850°C and performing a secondary heat treatment at a temperature in the range from 830°C to 840°C. in Addition, the secondary heat treatment can be carried out in several stages (in particular, in stage 2) at different temperatures within the above interval.

Each of the primary and secondary heat treatments in the method of manufacturing a superconducting wire and a superconducting multi-core wire in accordance with the present invention is preferably performed for at least 50 hours and at most 250 hours. In particular, is very suitable performing a secondary heat treatment for at least 100 hours.

Both heat treatment, primary and secondary, in the method of manufacturing a superconducting wire and a superconducting multi-core wire in accordance with the present invention can be performed in air atmosphere. In addition, this heat treatment is more preferably in a stream of air with the same components as in the atmospheric air. While it is preferable to reduce the moisture content in the atmosphere used in such treatments.

<Superconducting PR the water >

Superconducting wire in accordance with the present invention is an oxide superconducting wire containing oxide superconductor and a metal shell covering this oxide superconductor, and the material of the metal shell is characterized by a destructive deformation, which is within a certain range when tested stress-strain.

The aforementioned destructive deformation is preferably at least 30%, in particular at least 45%. In addition, destructive deformation is preferably at most 58%. The reason in this case are similar to those mentioned above in the description of the method of manufacturing a superconducting wire in accordance with the present invention.

The material used in the present invention the metal shell is preferably characterized by a maximum voltage of at least 180 MPa when tested stress-strain. The reason in this case are similar to those mentioned above in the description of the method of manufacturing a superconducting wire in accordance with the present invention.

The use of the material with the above properties as used in the present invention the metal shell is more effective in the case when the share of ACS is underwater superconductor in the superconducting wire in accordance with the present invention comprises at least 30%. In particular, the proportion of the oxide superconductor in the superconducting wire and superconducting stranded wire in which it is advisable to use a material with the above properties, is preferably at least 30%. The reason in this case are similar to those mentioned above in the description of the method of manufacturing a superconducting wire in accordance with the present invention.

As a material used in the present invention, metal shell, preferably using at least one metal selected from the group consisting of Ag, Cu, Fe, Ni, Cr, Ti, Mo, W, Pt, Pd, Rh, Ir, Ru and Os, and/or alloy based on the specified at least one metal. From the viewpoint of workability and chemical activity with respect to the oxide superconductor, particularly preferably using silver and/or silver alloy. The reason in this case are similar to those mentioned above in the description of the method of manufacturing a superconducting wire in accordance with the present invention.

The material used in the present invention, the oxide superconductor preferably contains an oxide superconductor on the basis of bismuth. For example, as described in the description of the method of manufacturing a superconducting wire in accordance with the present invention, this material preferably will gain an oxide superconductor on the basis of bismuth, obtained, for example, from mixed source powder containing powders of Bi2O3, PbO, SrCO3, CaCO3and CuO. The reason for this is that, when the superconducting wire is made suitable means, such as, for example, a method of manufacturing a superconducting wire in accordance with the present invention, it is possible to obtain the superconducting phase, which ultimately may have a high critical temperature, comprising at least 77 K.

<Superconducting stranded wire>

Superconducting stranded wire in accordance with the present invention is a superconducting stranded wire, containing many of the above-described superconducting wire and the second metallic shell covering these superconducting wires. Superconducting stranded wire in accordance with the present invention preferably has a ribbon-like shape. The reason in this case are similar to those mentioned above in the description of the method of manufacturing a superconducting multi-core wire in accordance with the present invention.

The properties of the metal shell and the oxide superconductor used in superconducting multi-core wire in accordance with the present invention, preferably similar to the properties of the metal is achieved membrane and the oxide superconductor, used in the superconducting wire in accordance with the present invention. The reason in this case are similar to those mentioned above in the description of the method of manufacturing a superconducting wire in accordance with the present invention.

Below is a detailed description of the present invention with reference to examples. However, the present invention is not limited to these examples.

<The first option exercise>

Powders of Bi2O3, PbO, SrCO3, CaCO3and CuO were mixed in a relationship 1,8:0,3:1,9:2,0:3,0 for the formation of the mixed powder, which is then subjected to heat treatments, respectively, at 700°C for 8 hours at 800°C for 10 hours and 840°C for 8 hours in the atmospheric air. The mixed powder was crushed after each heat treatment, which results in the original powder.

Silver tube with an outer diameter of 36 mm, an inner diameter of 33.5 mm, length 1000 mm, the oxide content of 50 ppm, a carbon content of 20 ppm and a purity (breakdown) of 4N silver filled above the original powder and subjected to extrusion in clad wire with a diameter of 3.7 mm and Fifty-five clad wires tied with giving them the hexagon shape and inserted into a tube of silver alloy with an outer diameter of 36 mm, an inner diameter of 28 mm illinoi 1000 mm, followed by extrusion in a stranded wire of diameter of 1.6 mm. in Addition, stranded wire laminated (primary rolling) to form a ribbon-like multi-strand wire.

The obtained thin stranded wire was subjected to a primary heat treatment in air atmosphere at 840-850°C for 50 hours. After this initial heat treatment of thin stranded wire again laminated (secondary rolling in like a stranded wire width of 4.0 mm and a thickness of 0.2 mm, which was then subjected to a secondary heat treatment in air atmosphere at 840-850°C for 50-150 hours to obtain the superconducting stranded wires. The number of cracks caused by pulling on the stages of manufacture of the superconducting stranded wires, checked by visual inspection, the results of which are presented in the table.

Table
Metal shellOxide superconductorThe number of cracks caused by stretching
typeBreaking strain (%)Max. stress (MPa)typeProportion (%)
Comparative example 1ser is Brany alloy 7,6273Bi22233315
Comparative example 2silver alloy12,1279Bi2223362
Comparative example 3silver alloy13,3257Bi2223335
Comparative example 4silver alloy21,7243Bi2223425
Comparative example 5silver alloy26,3232Bi2223432
Example 1silver alloy45,6191Bi2223430
Example 2silver alloy45,8188Bi2223330
Example 3silver alloy49,0185Bi2223420
Example 4silver alloy50,8184Bi2223330
Example 5silver alloy58, 178Bi2223400

Examples 2-5 and comparative examples 1-5

In examples 2-5 and comparative examples 1-5 superconducting stranded wires were obtained as in example 1 with use of a metal shell having the properties shown in the table, with the exception that the proportion of oxide superconductors were such, as shown in the table.

<Method of test stress-strain on the tube of silver and/or silver alloy>

Tube of silver and/or silver alloy used in examples 1-5 and comparative examples 1-5 were subjected to testing to determine the dependence of stress-strain using the machine for tensile tests with a speed of stretching 3 mm/min when the distance between the holders, 110 mm, to obtain values of strain at break (%) and maximum stress (MPa) respectively silver tubes and/or tubes from a silver alloy. The results of these tests are presented in the table.

Figure 3 shows a photograph showing how the tests stress-strain on the tube of silver and/or silver alloy used in examples and comparative examples of the present invention.

As shown by the above results the ATA, superconducting multicore wire according to comparative examples 1-5, which are applied in a tube of silver and/or silver alloy with strain at fracture less than 30%, has undergone many cracks caused by stretching during their manufacture. In contrast, the superconducting stranded wires according to examples 1-5, which are applied in a tube of silver and/or silver alloy with strain at fracture in at least 30%, did not undergo cracking caused by stretching during their manufacture.

Therefore, the superconducting stranded wires according to examples 1-5 were higher in quality than the wires according to comparative examples 1-5, as the metal materials of the membranes were characterized by a higher strain at fracture, which led to fewer cracks caused by pulling on the stage of their manufacture.

Examples 6-10

Example 1 used a silver tube of silver with a purity of 4N (99.99 percent). The concentration of impurities in such a silver tube of silver with a purity of 4N corresponds to 100 hours/million In examples 6-10 superconducting stranded wires were made as in example 1, except that in this case used a silver tube with the concentration of impurities, respectively, 5 h/m (example 6), 10 h/m (PR is measures 7), 50 h/m (example 8), 500 h/m (example 9) and 1000 h/m (example 10) to study the interdependence between the concentration of impurities in the metal sheath and cracking during processing. Examples of the impurities were Al, Fe, Cu, Ni, Si, Zn, etc.

During visual inspection for cracks caused by pulling on the stages of manufacture, it was found that cracks occurred at concentrations of impurities 5 h/m (example 6) and 1000 h/m (example 10). When considering these results together with the result in example 1, in which the silver tube has a concentration of impurities in 100 hours/million, found that the concentration of impurities is also an indicator of cracking during processing, and therefore, the frequency of occurrence of cracks during processing can be reduced by regulating the concentration of impurities, and that the metal shell is preferably the use of silver impurity concentration from 10 am/m to 500 hours/million

It should be understood that embodiments of and examples given in this description, all relations are illustrative and should not be considered restrictive. Scope of the present invention is not limited to the above description but only by the characteristics of the attached claims, and includes all modifications made within the scope of the claims and ek is ivalent.

1. A superconducting wire containing oxide superconductor and a metal shell covering the mentioned oxide superconductor, and the material mentioned metal shell test stress-strain characterized by destructive deformation in at least 30%.

2. Superconducting wire according to claim 1, in which the aforementioned destructive deformation is within the range from 30%to 58%.

3. Superconducting wire according to claim 1, in which the aforementioned destructive deformation is within the range from 45%to 58%.

4. Superconducting wire according to claim 1, in which the share of the mentioned oxide superconductor is in the range from 25 to 70%.

5. Superconducting wire according to claim 1, in which the material mentioned metal shell test stress strain is characterized by a maximum voltage of at least 180 MPa.

6. Superconducting wire according to claim 1, in which the material mentioned metal shell contains silver and/or silver alloy.

7. Superconducting wire according to claim 1, in which the material mentioned oxide superconductor contains an oxide superconductor on the basis of bismuth.

8. Superconducting wire according to claim 1, in which the material mentioned metal shell is a silver impurity concentration from 10 to 500 h/ml is.

9. Superconducting stranded wire, containing many superconducting wire according to claim 1 and the second metallic shell covering the aforementioned superconducting wire.

10. Superconducting stranded wire according to claim 9, having a ribbon-like form.

11. A method of manufacturing a superconducting wire, comprising the steps in which

fill a metal cylinder made of metal material shell, characterized by a test of the stress-strain destructive deformation within a range from 30%to 58%, the starting powder containing source material of oxide superconductor (S101); and

expose mentioned metal cylinder filled mentioned source powder, the pressure treatment at least once and the heat treatment at least once (S103).

12. A method of manufacturing a superconducting wire according to claim 11, in which the material mentioned metal shell is a silver impurity concentration from 10 to 500 hours/million

13. A method of manufacturing a superconducting stranded wires, including the stages at which

fill a metal cylinder made of metal material shell, characterized by a test of the stress-strain destructive deformation within a range from 30%to 58%, source powder containing source material of oxide superconductor (S201);

expose mentioned metal cylinder filled mentioned source powder, the pressure treatment at least once to get the wire (S203);

fill a metal cylinder that serves as a material of the second metal shell, many mentioned wires (S205); and

expose mentioned metal cylinder filled mentioned many mentioned wires, pressure treatment at least once and the heat treatment at least once to get the superconducting stranded wires (S207).

14. A method of manufacturing a superconducting multicore wire according to item 13, in which the material mentioned metal shell is a silver impurity concentration from 10 to 500 hours/million



 

Same patents:

FIELD: applied superconductivity.

SUBSTANCE: proposed composite superconductor that can be used to manufacture superconductors for superconducting windings suffering heavy mechanical loads (at operating pressure across conductor higher than 100 MPa) as well as for superconducting windings and devices operating under variable conditions, such as superconducting inductive energy storage devices, dipole and quadrupole magnets for charged particle accelerators, has superconducting material fibers, matrix of high-conductivity metal, such as copper and rare-earth intermetallide possessing high thermal capacity at low temperatures. Composite superconductor is provided with metal sheath accommodating rare-earth intermetallide; mentioned wires and conductor are welded together. Metal sheath can be made in the form of hollow cylindrical conductor or flat strip with hollow interlayer, their hollow spaces being designed to dispose rare-earth intermetallide. Composite superconductor is made in the form of a few multiple-fiber composite superconducting wires twisted around hollow cylindrical conductor accommodating rare-earth intermetallide. Composite superconductor can be made in the form of flattened single-lay strand of several multiple-fiber composite superconducting wires and several hollow cylindrical conductors of same diameter accommodating intermetallide which alternately vary within strand. Rectangular-section conductor is made of high-conductivity metal and has longitudinal groove.

EFFECT: enlarged functional capabilities.

7 cl, 8 dwg

The invention relates to high-temperature superconductivity and can be used for single core and multi-core composite conductors based on ceramics (Bi, Pb)(2)Sr(2)Ca(2)Cu(3)O(y) with high superconducting properties

FIELD: applied superconductivity.

SUBSTANCE: proposed composite superconductor that can be used to manufacture superconductors for superconducting windings suffering heavy mechanical loads (at operating pressure across conductor higher than 100 MPa) as well as for superconducting windings and devices operating under variable conditions, such as superconducting inductive energy storage devices, dipole and quadrupole magnets for charged particle accelerators, has superconducting material fibers, matrix of high-conductivity metal, such as copper and rare-earth intermetallide possessing high thermal capacity at low temperatures. Composite superconductor is provided with metal sheath accommodating rare-earth intermetallide; mentioned wires and conductor are welded together. Metal sheath can be made in the form of hollow cylindrical conductor or flat strip with hollow interlayer, their hollow spaces being designed to dispose rare-earth intermetallide. Composite superconductor is made in the form of a few multiple-fiber composite superconducting wires twisted around hollow cylindrical conductor accommodating rare-earth intermetallide. Composite superconductor can be made in the form of flattened single-lay strand of several multiple-fiber composite superconducting wires and several hollow cylindrical conductors of same diameter accommodating intermetallide which alternately vary within strand. Rectangular-section conductor is made of high-conductivity metal and has longitudinal groove.

EFFECT: enlarged functional capabilities.

7 cl, 8 dwg

FIELD: chemistry; electric wire.

SUBSTANCE: material in the form of oxide superconducting wire, which comprises oxide superconducting part and metal coating thereon, distinguishing itself by the fact that the above metal coating material during stress-strain relationship test features relative rupture strain of 30% or more.

EFFECT: material in the form of superconducting wire features high critical current density and is less susceptible to vertical cracking or breaking during manufacture.

14 cl, 3 dwg, 1 tbl, 10 ex

FIELD: electricity.

SUBSTANCE: thermo stabilised superconductors are implemented in the shape of matrix from metal or alloy, containing fibers of superconducting material and combination of rare-earth metals with extremely high heat capacity at low temperatures. At that superconductor contains at least two metallic tubes of unconditioned cross-section filled by combination of rare-earth metals and distance between tubes is not less then two tube linear dimensions. Superconductor has external envelope made from metal with high conducting properties. Tubes with combination of rare-earth metals can be distributed either by section of conductor as in matrix or by envelope.

EFFECT: extension of superconductor capabilities by means of increasing of its heat-absorbing abilities.

4 dwg

FIELD: electrical engineering.

SUBSTANCE: invention is related to the field of electric engineering, in particular, to superconductive cable, which contains frame (2), layer (3) of superconductive conductor formed around external periphery of frame (2), insulating layer (4) formed around external periphery of conductor layer (3), screening layer (6) formed around external periphery of insulating layer (4), and normally-conductive metal layer (5) formed between insulating layer (4) and screening layer (6). Normally-conductive metal layer (5) is located inside the screening layer (6), has inductivity higher than of screening layer (6).

EFFECT: provides suppression of temperature rise in case of accidents, such as short circuits, and reduction of AC losses in normal mode of operation, since high currents flow through screening layer.

10 cl, 3 dwg

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, particularly to super-conducting cable capable to absorb thermal compression of super-conducting wire. Super-conducting cable comprises a super-conducting wire coiled to form a super-conducting layer (layer-conductor) (13), reverse conductor (17), a layer of strain relaxation (12), an insulating layer or an outer strain relation layer (16) arranged on the super-conducting layer outer side and cable carcass, (11) arranged on the strain relaxation layer inner side.

EFFECT: superconducting layer compression absorption by cooling superconducting wire with coolant.

9 cl, 4 dwg, 1 tbl

Power cable line // 2366016

FIELD: electrical engineering.

SUBSTANCE: in a line for transmitting and distributing direct current a power cable line is provided, which makes easier supply of electricity to various devices used for operation of that line. The power cable line comprises power cables (1lg, 1r, 1p, 1m, 1n), which transmit and distribute direct current, a unit (2) for superimposing an alternating current component on these cables, and an electricity tap off unit (3), meant for tapping off power of the superimposed alternating current component from this cable. Unit (2) superimposes the alternating current component on the power cable, and electrical energy of the alternating current is transmitted together with electrical energy of direct current on the power cable. The tap off unit (3), located at a certain section of the cable, taps off this alternating current component and transmits it to different devices.

EFFECT: invention allows for designing a cable, which makes easier tapping off electrical energy during transmission of direct current.

4 cl, 13 dwg

FIELD: physics; conductors.

SUBSTANCE: invention relates to making composite superconductors with improved current-carrying capacity and can be used, particularly, for making superconducting magnet windings. According to the invention, the multi-layer tape nanostructure composite based on a superconducting niobium-titanium alloy contains alternating layers of niobium and niobium alloy-(25-45) wt % titanium, with layer thickness of not more than 50 nm. The thickness of each niobium layer is 50-70% of the alloy layer thickness.

EFFECT: obtaining a composite with critical current density of 58000 A/cm2 in a magnetic field with flux density of 6 T.

2 cl, 3 tbl

FIELD: physics; conductors.

SUBSTANCE: invention relates to making composites with improved current-carrying capacity and can be used, particularly, for making superconducting magnet windings. According to the invention, the method of making multi-layer tape nanostructure composites based on a niobium-titanium alloy for composite superconductors involves multi-cycle rolling, each cycle of which involves assembling a packet from alternating plates of niobium and a niobium-titanium alloy, attaching the plates to each other into a packet through diffusion welding at temperature 800-900°C and pressure 20-40 MPa for 0.5-3 hours, hot vacuum rolling and cold rolling. In the first cycle, the initial plates are components of the composite, and in the second and following cycles - plates, obtained from the previous cycle. To stabilise the superconductor before the last rolling cycle, the welded packet is put into a copper casing. Thickness of the copper casing is 3-25% of the thickness of the packet.

EFFECT: increased critical current density.

2 cl, 2 tbl, 6 ex

FIELD: metallurgy.

SUBSTANCE: on surface of plate made from titanium it is located powder of high-temperature superconducting (HTSC) compound and it is implemented cold deformation by means of rolling with receiving of preferred-orientation scales of HTSC compound. Scales are separated from substrate, it is collected multilayer packet from scales with alternating spacers from silver and it is pressed with formation of multilayer composite silver-HTSC-silver. Composite is placed into envelope made of silver, it is rolled with receiving of band of specified geometry and is thermal treated at temperatures in the range 800-930°C during 20-100 hours.

EFFECT: increasing current-carrying ability of band and filling factor by superconductor.

2 ex

FIELD: electricity.

SUBSTANCE: invention relates to electrical engineering, specifically to thermo-stabilised superconductors based on the Nb3Sn compound and methods of making the said superconductors. The thermo-stabilied superconductor based on the Nb3Sn compound is made in form of a matrix from a metal or alloy, containing superconducting material fibre, metal tubes filled with a rare-earth metal compound with extremely high heat capacity at low temperatures, an outer hollow copper cylinder and a thin cylindrical shell made from titanium and/or niobium placed coaxially between the matrix and the outer hollow copper cylinder. The metal tubes are tightly pressed to each other in the gap between the cylinder and the shell in the first version, or in a gap made in the radial direction in the wall of the cylinder in the second version. The method of making such thermo-stabilised superconductors is described.

EFFECT: wider functional capabilities of a thermally insulated superconductor due to presence in the superconductor of a rare-earth intermetallic compound with extremely high heat capacity at helium temperatures, which increases mean heat capacity of the superconductor by 5-6 times.

12 cl, 11 dwg

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