JPH0736479B2 - Manufacturing method of Nb-Ti superconducting magnetic shield material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing an Nb-Ti based superconducting magnetic shield material.

(Prior Art) Conventionally, type 1 superconductors and type 2 superconductors have been used as magnetic shield materials utilizing superconductivity. Both are properly used depending on the strength of the magnetic field, and the Type 1 superconductor can be completely magnetically shielded by the Meissner effect, although at a considerably low magnetic field. The second-type superconductor has a lower critical magnetic field (H _C1 ) and an upper critical magnetic field (H _C2 ), and although it is a fairly low magnetic field up to H _C1 , it can be completely magnetically shielded by the Meissner effect. Between H _C1 and H _C2, a magnetic shield can be performed in a mixed state of a superconducting state and a normal conducting state, but H _C2 is extremely high and a magnetic field with a high magnetic field is also possible.

Conventionally, the magnetic shielding material using the Nb-Ti-based superconducting material, which is a type 2 superconductor, has unstable superconducting characteristics by itself.
It had a structure in which it was coated with a highly conductive metal such as Cu or Al, or was alternately laminated, and was generally in the shape of a tape or sheet.

(Problems to be Solved by the Invention) In Nb-Ti based alloys, the magnetic shield property increases as the force to catch the magnetic flux that has penetrated into the superconductor at pinning points such as precipitated particles and dislocation networks increases. Particularly, when the precipitation of α-Ti fine particles is performed with an optimum size and distribution by a combination of appropriate heat treatment and cold working, the magnetic shield characteristics are greatly improved.

On the other hand, for superconducting materials, Cu is used to stabilize the superconducting properties.
It is necessary to adhere a highly conductive metal such as Al or Al. This is because heat is generated due to the rapid penetration of magnetic flux into the superconducting plate, but the highly conductive metal plates are in close contact with both sides of the superconducting plate so that they can be quickly diffused into the external liquid helium. When a heat treatment for improving the magnetic shield characteristics as described above is performed after the highly conductive metal is adhered, an intermetallic compound brittle at the interface due to diffusion of a metal element between the two, for example, Cu / Nb-Ti superconducting material In, a Cu-Ti compound or the like is formed, and subsequent processing becomes impossible, or even a slight strain causes material destruction.
Further, the composition of the superconducting material may change to deteriorate the superconducting property, or the impurity element may diffuse into the highly conductive metal to deteriorate the conductivity, resulting in deterioration of the stabilizing property.

Therefore, it is almost impossible to perform heat treatment after composite integration with a magnetic shield material having a structure in which thin films of a high-conductivity metal and a superconducting material that have been conventionally used are alternately combined and integrated. I couldn't expect any improvement.

Therefore, it has been attempted to perform soldering, cladding, vapor deposition, sputtering, plating, etc. after subjecting a superconducting material to appropriate heat treatment or processing in advance, but in the case of soldering, the conductivity is Cu or Al. The stability was poor because it was not so good. Furthermore, its mechanical strength was low and the adhesion strength was poor. In addition, the metallic adhesion of the clad does not improve unless it is hot-processed to some extent, but unnecessary heat is added to decompose the fine particles precipitated in Nb-Ti, which results in magnetic shielding properties. However, there was a problem that Furthermore, deposition, sputtering, plating, etc. can be applied relatively easily, and the adhesion is also moderate, but it is suitable for thin films, and it takes too much time to deposit a thick and sufficient amount, and the cost is low. There are problems such as being bulky and not being easy to form multiple layers.

In the case of Nb-Ti based superconducting wire, aging heat treatment
-Since the Ti particles were precipitated, cold working was performed to elongate the precipitated particles, which together with the dislocation network introduced at the same time serve as pinning points for the magnetic flux, which was suitable for relatively high magnetic fields. Therefore
The Nb-Ti based superconducting magnetic shield material was also subjected to the aging heat treatment and cold working as described above, but unlike the wire material,
Although it depends on the thickness, it had already lost its shielding ability in the low magnetic field range.

In view of the above problems, the present invention is capable of composite-integrating a highly conductive metal into a Nb-Ti alloy superconducting material at a free volume ratio,
Both layers can be easily laminated in multiple layers, and it is possible to perform suitable heat treatment or processing after combining them to obtain good metallic adhesion, and as a result, Nb-Ti with even higher magnetic shielding properties can be obtained. A method for manufacturing a superconducting magnetic shield material.

(Means for Solving the Problem) The present invention is directed to at least one layer of highly conductive metal Cu or
Al and Nb-Ti alloy is alternately laminated Nb-Ti in the method of manufacturing a superconducting magnetic shield material, Nb or in a housing-like or cylindrical hollow body made of a metal with high conductivity
At least one layer of Nb-Ti alloy plate coated with Ta foil is filled so as to be alternately laminated with the metal having high conductivity,
After the filling rate is 60% or more, the end of the hollow body is closed, the inside is evacuated, and the interior is welded and sealed to form an integrated composite. The integrated composite has a processing rate of 30 to 98% and a temperature of 500 to 100.
Hot working at 0 ℃, heat treatment at a temperature of 300-450 ℃ for 1 to 168 hours, and processing rate of 3
It is characterized in that 0 to 98% of cold working is alternately repeated up to 6 times to form a plate or foil, and then a final heat treatment is performed at a temperature of 300 to 450 ° C. and a holding time of 1 to 1000 hours. Nb-T
This is a method for manufacturing an i-based superconducting magnetic shield material. After the final heat treatment, it is preferable to perform cold working with a working rate of 2% or more and less than 30%.

(Operation) Hereinafter, the operation of the present invention will be described in detail with reference to the drawings.

As shown in Fig. 3, the Nb-Ti alloy layer and Cu or Al are usually used.
The plate-shaped or foil-shaped superconducting magnetic shield material having a multi-layer structure in which a number of layers are alternately laminated has a significantly improved shield characteristic as compared with a single-layer superconducting magnetic shield material having the same structure.

The reasons are as follows. The reason why the shield property is high is that the pinning force is large,
A large number of pins having a smaller thickness have been introduced for some reason. This is considered to be because in the case of the present invention, the cold working rate is increased and the precipitation driving force of the precipitates that become the pins is increased. In addition, the multi-layer has a higher cooling efficiency even if there is a local heat generation due to the flux jump, and is excellent in stability. The manufacturing method of the present invention is optimal for that purpose. Among them, a fairly long heat treatment is required at a temperature at which Cu-Ti or Al-Ti compound can be formed, but when this compound is formed, the workability is completely deteriorated as described above, and the subsequent good Processing becomes impossible. Here, the barrier layer of Nb or Ta existing between the high-conductivity metal layer and the Nb-Ti-based alloy layer can almost prevent the diffusion of the metal element between them during the heat treatment, and thus the magnetic layer according to the present invention can be prevented. With the shield material, high magnetic shield characteristics can be obtained while maintaining good workability. Since the workability is good, the thickness of the shield material can be reduced to the order of several tens of μ, and the weight of the shield material can be reduced and the material cost per unit area of the shield material can be reduced.

Further, as shown in FIG. 1 (b), the Nb-Ti alloy plate 1 and the metal plate 4 having high conductivity are alternately laminated in the hollow body 3 having a metal structure having high conductivity. Since this is a method, it is possible to freely select the volume ratio of the both, it is easy to make multiple layers, and the number of layers can be increased freely. FIG. 1 (a) shows the case where only one layer of Nb-Ti alloy plate is inserted. Here, the filling rate inside the hollow body 3 is set to 60% or more because when it is less than 60%, each member is distorted in the initial stage of processing, resulting in poor adhesion and material destruction. As for the shape of the hollow body 3, in addition to the housing shape as shown in FIG. 1, a cylindrical shape as shown in FIG. 6 and the like are also possible.

Further, as shown in FIGS. 1 (a) and 1 (b), the Nb-Ti alloy plate 1 has a Nb or Ta foil 2 wound and coated on the entire surface, which is used for hot working and heat treatment. In this case, it becomes a diffusion barrier between the Nb-Ti alloy and the metal with high conductivity, has good workability to prevent the formation of harmful compounds such as Cu-Ti, and has a high magnetic property by sufficient heat treatment. The shield characteristic can be obtained.

Further, as shown in FIGS. 2 (a) and 2 (b), a lid 5 is attached to the end of the housing-shaped hollow body 3 and the inside is evacuated and sealed by electron beam welding or the like. There is no internal oxidation during processing or heat treatment, and good metallic adhesion between each member is obtained, and an integrated composite having good workability is obtained.

The Nb-Ti single-layer composite shown in FIG. 2 (a) is processed into a thin plate, and then laminated and sealed as shown in FIG. 2 (c) and processed into a multilayer as shown in FIG. It is also possible to use the magnetic shield material 7.

Before performing heat treatment and processing on the integrated composite, hot working is performed by heating to a certain degree to soften each member, and then pressure-bonding by a method such as rolling, forging, extrusion, and good metal adhesion. Is to get. The temperature is set to 500 to 1000 ° C. because the temperature is less than 500 ° C.
The b-Ti alloy is still hard and sufficient adhesion cannot be obtained.
If it exceeds, the Cu of the metals having high conductivity approaches the melting point and becomes too soft, and the mismatch with the hardness of the Nb-Ti alloy becomes large, resulting in a decrease in adhesion. However, when using Al having a low melting point of 660 ° C., it goes without saying that hot working is performed at a temperature lower than that. In addition, the processing rate is 30 ~
The reason for setting it to 98% is that if it is less than 30%, it is difficult to obtain sufficient adhesion even if the temperature is high, and if it exceeds 98%, the cold working rate necessary for improving the magnetic shield characteristics cannot be obtained.

The reason why the heat treatment temperature is 300 to 450 ° C is that the precipitation rate of α-Ti fine particles, which is an important pinning point, is too small and the time is too long below 300 ° C. This is because the deposited particles become coarser and rather lead to deterioration of the magnetic shield characteristics. The holding time per heat treatment is set to 1 to 168 hours because the absolute amount of precipitation is insufficient if it is less than 1 hour, and the precipitation is almost saturated if it exceeds 168 hours. This is because a remarkable effect cannot be obtained.

Also, the driving force for precipitation is the lattice defects such as dislocations and vacancies introduced by cold working, and it is more effective if cold working is performed to some extent before the heat treatment. Alternately repeating the hot working and the heat treatment has a further effect. The reason why this number of repetitions is set to 6 times or less is that if it exceeds 6 times, the cold working ratio between the respective heat treatments cannot be made sufficiently high, and the effect also reaches the ceiling.

Furthermore, when heat treatment and cold working are alternately performed a plurality of times, the cold working ratio of 30 to 98% per heat treatment or until reaching the final shape is introduced at less than 30%. The amount of lattice defects is insufficient and the effect of heat treatment cannot be utilized. If it exceeds 98%, part or all of the material is destroyed and processing defects occur, or the thickness at the start of processing becomes too large. This is because, in reality, it becomes impossible to manufacture.

In addition, the final heat treatment after cold working to the final plate thickness is because a precipitate of α-Ti particles effective as a pinning point in the magnetic field in the range of magnetic shielding is obtained, and This is because there is a synergistic effect with the precipitate formed and processed. The temperature range of this heat treatment is set to 300 to 450 ° C. as in the case of the heat treatment described above. Also,
When the holding time is set to 1 to 1000 hours, the absolute value of precipitation is insufficient if it is less than 1 hour, and if it exceeds 1000 hours, the precipitation is almost saturated, and even if the time is further extended, a remarkable effect cannot be obtained. Because.

Next, the plate or foil that has been subjected to the final heat treatment has a processing rate of 2%.
It is preferable to carry out the cold working of not less than 30%, because the properties are improved as compared with the final heat-treated finished material. If the working rate is less than 2%, the effect of cold working is not sufficient, and 30%
This is because in the above, the decrease is remarkable beyond the optimum region.

(Example) Example 1 Nb-46wt having a thickness of 5 mm, a width of 100 mm, and a length of 150 mm, which was obtained by winding and covering a surface of a foil 2 of Nb having a thickness of 0.1 mm as shown in Fig. 1 (b).
% Ti alloy plate 1 and 6 oxygen-free copper plates 4 whose thickness is changed to 2 mm, outer size is 58 mm thick, 112 mm wide, 172 mm long.
mm, the inner size is 50 mm thick, the width is 102 mm, and the length is 172 mm.
As shown in FIG. 2B, both ends of the hollow body 3 were covered with a lid 5 having a size adapted to the hollow portion, and the joints were welded and sealed while vacuuming to form an integrated composite body.

After that, heat up to 750 ℃ and hot-roll it to a thickness of 27 mm.
Then, cold rolling and heat treatment were performed as shown in Table 1 to measure the magnetic shield characteristics as a disk-shaped sample having a thickness of 0.1 mm and a diameter of 50 mm. The method of the measurement, the external field B ₁ magnetic shield Sample 8 as shown in FIG. 4
It is set vertically in (magnetic field when there is no sample), the residual magnetic field B ₂ when the sample is set is measured by a Hall element, and the magnetic shield characteristic is evaluated by the magnitude of ΔB obtained by the following formula. . The results are shown in Table 1.

ΔB = B ₁ -B ₂ also, .DELTA.B although increases .DELTA.B almost .DELTA.B = relation B ₁ because until a certain value B ₁ superconductor is a complete magnetic shielding space with Hall elements, from a certain point Since the magnetic flux penetrates into the space with the Hall element, the rate of increase begins to take place, and then it peaks and then gradually decreases. Therefore, Seff = 100 × ΔB / B ₁ (%) was used as the shield efficiency, and Seff particularly when B ₁ = 0.5 Tesla was used as an index for evaluating the magnetic shield characteristics. The general relationship between B ₁ and ΔB is shown in FIG.

The intermediate working rate in Table 1 is the cold working rate performed between one heat treatment and the next heat treatment, and the final working rate is the cold working rate performed immediately before the final heat treatment. .

In Nos. 1 to 12, the magnetic shield characteristics were observed by changing the intermediate heat treatment condition and the number of repetitions while keeping the intermediate heat treatment ratio, the final heat treatment ratio, and the final heat treatment conditions constant. However, in No. 1 and 10 in which the number of repetitions was 1, no intermediate processing was performed. No.1 ~ 5
If the heat treatment temperature is relatively low, the holding time should be considerably long (No. 1), and if it is high, the holding time should be short and the number of repetitions should be increased (No. 2 to 5). Improved. Especially under the conditions of No. 2 and 3, high values were obtained characteristically.

In Nos. 6 to 12, one of the three conditions of the temperature of intermediate heat treatment, the holding time, and the number of repetitions was changed with respect to any of Nos. 1 to 5. Since they do not meet the requirements, they all have extremely low magnetic shield characteristics. Some of them, like No. 11, could not be processed due to material damage during the final processing. In Nos. 13 to 14, the number of repetitions of the intermediate heat treatment and the intermediate working rate were changed with respect to No. 2. The intermediate processing rate is close to the limit, and the characteristics are not so good compared to No.2.

No. 15 is 99% with only the intermediate processing rate of No. 14 further increased.
However, it became impossible to process due to material damage during the final processing.

In No. 16-17, the final processing rate was changed from No. 2. The final processing rate is near the limit, and No. 16 is not so good in characteristics compared to No. 2. No. 17 is quite good in terms of characteristics, but No. 17
A little lower than 2.

No. 18 is 25% with only the intermediate machining rate of No. 16 further reduced.
However, the characteristics were extremely low.

Nos. 19 to 21 are different from No. 2 in one of the two conditions of the final heat treatment temperature and the holding time. Since they do not meet the requirements, they all have extremely low magnetic shield characteristics.

In Nos. 22 to 23, only the holding time of the final heat treatment was changed from No. 2. In No. 22, the characteristics were improved considerably by extending the time to 500 hours. No. 23 is close to the limit and the characteristics are degraded.

No. 18 is a product in which the holding time of No. 23 was extended by 100 hours, but the characteristics were further deteriorated.

Example 2 A sample in which an integrated composite body (Fig. 1 (b)) was prepared in the same manner as in No. 2 of Example 1, and then cold worked at different working rates as shown in Table 2. Then, the magnetic shield characteristics were measured in the same manner. However, the index of the characteristic is expressed as a percentage of increase / decrease with respect to No. 2 Seff at 0.5 T.

No.25 is the No.2 final heat-treated rolled material that was cold-worked at a working rate of 15%, and a characteristic improvement of 30% over No.2 was observed.
Nos. 26 and 27 have the same cold working ratios as the lower limit and the upper limit, respectively, and although a slight improvement in properties can be seen compared to No. 2, the effect is considerably lower than No. 25.

No. 28 to 29 are the same as above, but the processing rate does not meet the requirements, but No. 28 did not change the characteristics at all compared to No. 2. No.
In No. 2, the characteristics of No. 29 were lower than those of No. 2.

Example 3 An integrated composite body (FIG. 1 (b)) was prepared in the same manner as in Example 1, and the subsequent processing was carried out under the same conditions except for hot working (in this case, hot rolling). The workability and the magnetic shield characteristics were examined by changing the values as shown in Table 3. The workability is the same as No.2, which was subjected to the same heat treatment and cold rolling and was successfully processed to a final size of 0.1 mm in thickness, and ◎, and those with defects such as edge cracks, pinholes and breaks in the middle. The order of occurrence, the size of the defect, the frequency, etc. were marked as ◯, Δ, and ×. The results are shown in Table 3 together with the magnetic shield characteristic Seff of 0.5T. However, for No. 37 only, the final processing rate was 31% due to its thickness size restriction.

No. 2 is the same as No. 2 in Table 1, and Nos. 30 to 31 have the hot working rate of 54%, which is the same as in Example 1, and only the heating temperature is changed. As a result, No. 2 was the best, few defects were generated, and the magnetic shield characteristics were also good. No. 30 has very good characteristics when the heating temperature is made quite low,
After all, the adhesion was lowered and various defects were generated. No.31 had a fairly high heating temperature, but its workability was almost the same as that of No.2, but its properties were slightly degraded.

Since the heating temperature of No. 32 was lower than that of No. 30, the adhesion was extremely poor and the final size could not be reached. In No. 33, the heating temperature was too high, and the phenomenon of copper melting due to heat generated during processing occurred during hot rolling.

Moreover, the heating temperature of Nos. 34 to 37 was fixed at 750 ° C, which was the best in terms of workability and characteristics, and only the hot working rate was changed. As a result, No. 34 had good characteristics, but some defects which were considered to be due to insufficient adhesion occurred. Since No. 35 had an extremely high hot working rate, the cold working rate was reduced by that amount, and the characteristics were significantly reduced. Since No. 36 had a smaller hot working rate than No. 34, adhesion was insufficient and material rupture occurred one after another, making it impossible to machine to the final size. In No. 37, the hot workability was too high, so the cold workability after the final heat treatment was only 31%, and although the workability was reasonably good, the properties were remarkably low.

Example 4 When an integrated composite body (FIG. 1 (b)) was prepared in the same manner as in Example 1, the filling rate was changed as shown in Table 4, and heat treatment and processing were performed under the same conditions as No. 2. Then, the workability was investigated. The evaluation was performed in the same manner as in Example 3. The results are shown in Table 4. The filling rate of each of the integrated composites of Example 1 was 95%, and in each of the Examples, good processing was possible up to the final size.

No. 38 had some defects in the vicinity of the final size, but had moderately good workability. However, in No. 39, the workability was very poor because the material often fractured due to poor internal adhesion.

Example 5 When an integrated composite body (Fig. 1 (b)) was prepared in the same manner as in Example 1 and no Nb foil 2 was used, material fracture frequently occurred during cold working, In addition, the broken part is SEM
Moreover, a large number of Cu-Ti compounds were detected by the EPMA and EPMA.

Example 6 When an integrated composite body (FIG. 1 (b)) was prepared in the same manner as in Example 1, no sealing by electron beam welding in a vacuum was performed, and it was found that during the cold working, adhesion Frequent material breakage, which is thought to be due to defects. It was presumed that this was because the contact surface inside the composite material was oxidized during hot working and the metal adhesion was insufficient.

Example 7 When an integrated composite body (FIG. 1 (b)) was prepared in the same manner as in Example 1, all of the oxygen-free copper plate 4 and the housing-shaped hollow body 3 were changed to pure aluminum materials, and When the same heat treatment and cold working as in Table 1 were applied except that the heating temperature in hot rolling was set to 520 ° C., similar magnetic shield characteristics were obtained within the range of variation, respectively. Details are omitted.

Example 8 When an integrated composite body (Fig. 1 (b)) was prepared in the same manner as in Example 1, the Nb-Ti alloy plate 1 was replaced with an Nb-60wt% Ti alloy plate, and the others were used. When subjected to the same heat treatment and cold working as in Table 1, it was 10 to 20% higher than the Nb-46wt% Ti alloy, and stable magnetic shield characteristics were obtained within the range of variation, but details are omitted. To do.

When an integrated composite body (Fig. 1 (b)) was prepared in the same manner as in Example 1, the Nb-Ti alloy plate 1 was replaced with a Nb-30wt% Ti alloy plate, and the others were shown in Table 1. When the same heat treatment and cold working were performed, a stable magnetic shield characteristic was obtained within the range of variation, although it was 10 to 20% lower than that of the Nb-46 wt% Ti alloy, but details thereof are omitted.

When an integrated composite body (Fig. 1 (b)) was prepared in the same manner as in Example 1, the Nb-Ti alloy plate 1 was treated with Nb-40wt% Ti-10wt% Z.
When the heat treatment and cold working similar to those in Table 1 were applied instead of the r alloy plate, it was about 20 to 30% lower than the characteristics of the Nb-46wt% Ti alloy, but within the range of variations. Although stable magnetic shield characteristics were obtained in, the details are omitted.

Also, when the same heat treatment and cold working as in Table 1 were performed except that the plate was made of Nb-40wt% Ti-50wt% Ta alloy,
Although it was about 20 to 30% lower than the characteristics of the Nb-46wt% Ti alloy, stable magnetic shield characteristics were obtained within the respective variations, but details are omitted.

(Effects of the Invention) As described above, according to the present invention, it is possible to obtain stable magnetic shield characteristics of several times or more, and in some cases, 10 times or more of that of the comparative example, and stabilizing metal and Nb-Ti system. In addition to being able to easily assemble an integrated composite with a superconducting material, it can be subjected to heat treatment and cold working necessary for improving the magnetic shield characteristics, and has good workability. Therefore, the magnetic shield material can be thinned to a foil shape, and the characteristics are also very good, so it is possible to bring high performance while responding to the recent demand for weight reduction such as magnetic levitation trains and electromagnetic propulsion ships. Its industrial utility value is extremely high.

[Brief description of drawings]

FIG. 1 (a) is a view showing a case where one layer of Nb-Ti based alloy sheet coated with Nb foil is inserted into a hollow body of oxygen-free copper casing, FIG. 1 (b). Shows a diagram in which Nb-Ti alloy plate and oxygen-free copper plate are alternately laminated and inserted,
FIG. 2 (a) is a view showing a cross section in the longitudinal direction of the integrated composite of FIG. 1 (a) with oxygen-free copper lids attached to both ends, and FIG. 2 (b) is of FIG. 1 (b). The figure which shows the cross section of the longitudinal direction of what attached the lid | cover of oxygen-free copper to the both ends of the integrated composite body,
Fig. 2 (c) shows the single-layer composite material of Fig. 1 (a), which is thinned by processing, then a plurality of sheets are stacked and inserted, and an oxygen-free copper lid is attached to both ends in the longitudinal direction of the integrated composite body. FIG. 3 is a diagram showing a cross section of FIG. 3, FIG. 3 is a diagram showing a magnetic shield material obtained by the method of the present invention, and FIG. 4 is a situation in which a disk-shaped sample of the magnetic shield material is placed in a vertical magnetic field to measure magnetic shield characteristics. Fig. 5 is a diagram plotting the change of the magnetic shield characteristic ΔBm when the external magnetic field is increased, and Fig. 6 is a graph showing the conductivity of Nb-Ti alloy and conductivity in the cylindrical hollow body. It is a figure which shows the condition which laminated | stacked the high metal. 1 ... Nb-Ti alloy plate, 2 ... foil, 3 ... hollow body,
3 '... metal layer with high conductivity, 4 ... metal plate with high conductivity, 5 ... lid, 6 ... metal layer with high conductivity, 7 ...
… Multilayer magnetic shield material, 8 …… Magnetic shield sample.

Front page continued (72) Inventor Norihiro Shimizu 3434 Shimada, Hikari City, Yamaguchi Pref., Nippon Steel Co., Ltd.Hikari Steel Works (72) Inventor, Tsutomu Sasaki 1618 Ida, Nakahara-ku, Kawasaki City, Kanagawa Nippon Steel Co., Ltd. Inside the Institute of Technology

Claims (2)

[Claims] 1. A method for producing an Nb-Ti-based superconducting magnetic shield material in which at least one layer of a highly conductive metal Cu or Al and an Nb-Ti-based alloy are alternately laminated, wherein the metal having a high conductivity is used. At least one layer of Nb-Ti alloy plate coated with Nb or Ta foil is filled in a case-like or cylindrical hollow body made of, so as to be alternately laminated with the metal having high conductivity, and the filling rate is increased. After 60% or more, the end of the hollow body is closed, the inside is vacuumed and welded and sealed to form an integrated composite, and the integrated composite has a processing rate of 30 to 98% and a temperature of 500 to 100.
Hot working at 0 ℃, heat treatment at a temperature of 300-450 ℃ for 1 to 168 hours, and processing rate of 3
It is characterized in that 0 to 98% of cold working is alternately repeated up to 6 times to form a plate or foil, and then a final heat treatment is performed at a temperature of 300 to 450 ° C. and a holding time of 1 to 1000 hours. Nb-T
Manufacturing method of i-based superconducting magnetic shield material. 2. After the final heat treatment, the processing rate is 2% or more.
The method for producing a Nb-Ti based superconducting magnetic shield material according to claim 1, wherein cold working is performed at less than 30%.