JPH04202062A - Production of hermetically sealed vessel made of high temperature superconducting material - Google Patents

Abstract

PURPOSE:To easily obtain a hermetically sealed vessel lined with a dense high temp. superconducting film by dividing a vessel into two vessels, forming contact faces at the dividing parts of the two vessels, coating the contact faces and the insides of the vessels with powder of a precursor of a high temp. superconducting material, combining the vessels in one body and carrying out sintering in an atmosphere under pressure. CONSTITUTION:A vessel is divided into two vessels 4, 5 and contact faces 10 having a large contact area are formed at the dividing parts of the vessels 4, 5. The contact faces 10 and the entire insides of the vessels 4, 5 are coated with powder 11 of a precursor of a high temp. superconducting material in the form of a layer. The vessels 4, 5 are then combined in one body by allowing the faces 1 0 to coincide with each other and one or more through holes 7 are pierced in the vessels 4, 5. The combined vessels 4, 5 and the powder 11 are sintered in an atmosphere under pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a sealed container made of high temperature superconducting material.

[Prior Art] In recent years, the development of so-called ceramic-based high-temperature superconducting materials such as yttrium-based, bismuth-based, and thallium-based materials has progressed. There is a need for technology to form materials into arbitrary shapes.

Among these, we manufacture sealed containers made of high-temperature superconducting materials as magnetic shielding containers for NMR (nuclear magnetic resonance diagnostic equipment) used in the medical field and accelerators for high-frequency acceleration cavities used in the field of high-energy physics. is requested.

When manufacturing such a sealed container made of high temperature superconducting material,
Manufacturing as shown in FIG. 7 is being considered.

In the figure, 1 is a sealed container made of high-temperature superconducting material, 2.3 is a divided container obtained by dividing the sealed container 1 made of high-temperature superconducting material, 4.5 is a container type that constitutes the external shape of divided containers 2 and 3, and 6 is a divided container. Container body 4
, 5 is a so-called ceramic-based high-temperature superconducting film such as yttrium-based, bismuth-based, thallium-based, etc., formed in a layered manner on the entire inner surface of the container. In a high-frequency acceleration cavity accelerator, the through-hole serves as a terminal through which elementary particles pass. 8
9 is a joint between the divided containers 2 and 3, and 9 is a joint formed at the joint 8 by brazing, laser welding, or the like.

Then, a divided container body 4.5 is formed as a mold for a divided container 2.3 formed by dividing the sealed container 1 made of high temperature superconducting material, and a precursor obtained by pulverizing high temperature superconducting material that has been baked and hardened in advance to have a high density is formed. Dissolve the body with a binder to form the divided container body 4.5
is coated in a layer on the entire inner surface of the container, and is sintered in the atmosphere to form a divided container 2.3 having a high temperature superconducting film 6 inside.
The divided containers 2 and 3 are butted together at the mating portion 8, and the 4.5 portion of the divided container body at the mating portion 8 is brazed, laser welded, or the like to form a joint portion 9.

[Problems to be Solved by the Invention] However, by sintering the precursor in the atmosphere, a high temperature superconducting film 6 is formed inside the divided container body 4.5, and the divided container 2
．． 3, and the divided containers 2.3 are butted together to form a divided container body 4.
, 5 are bonded together, since the precursor is sintered in the atmosphere, the gaps in the high-temperature superconducting film 6 after the binder evaporates remain inside the high-temperature superconducting film 6, resulting in a dense film. is not formed, and therefore a high-performance high-temperature superconducting container cannot be obtained, there are problems that the six high-temperature superconducting films are not properly bonded to each other, and there are problems that the process becomes complicated.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a method for manufacturing a sealed container made of a high-temperature superconducting material, which has simple steps and can obtain high superconducting performance.

[Means for Solving the Problems] The present invention forms contact surfaces that have a large contact area and can abut against each other at divided portions of divided container bodies that are formed in advance to constitute a sealed container, After applying a layer of a precursor of high-temperature superconducting material to the entire inside surface of each divided container body and the contact surface, the contact surfaces of each divided container body are brought into contact with each other and the divided container bodies are assembled into one body. A sealed container made of a high-temperature superconducting material, characterized in that a through hole is formed in at least one place in each divided container body, and then the combined divided container body and the precursor material are sintered in a pressurized atmosphere. It concerns a manufacturing method.

[Function] According to the present invention, a contact surface having a large contact area and capable of abutting and mating is formed at the divided portions of divided container bodies formed by dividing a sealed container, and the entire interior surface of each divided container body is formed. After applying a layer of a precursor of a high temperature superconducting material to the abutting surfaces, the abutting surfaces of each divided container body are brought into contact with each other to assemble the divided container bodies into one body. By forming a through hole in at least one of the parts and then sintering the combined divided container body and the precursor in a pressurized atmosphere, a dense high-temperature superconducting thick film can be produced in a simple process. A sealed container made of superconducting material is manufactured.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show a first embodiment of the present invention.

It should be noted that the parts in the figure with the same reference numerals as those in FIG. 7 are the same, and therefore their explanation will be omitted, and only the characteristic parts of the present invention will be explained below.

In FIG. 1, reference numeral 10 indicates contact surfaces such as flanges formed on the divided parts of the divided container body 4.5 obtained by dividing the sealed container A into a plurality of parts, which have a large contact area and can come into contact with each other; A precursor coating is coated in a layer on the entire inner surfaces of the divided container bodies 4 and 5 and on the mating surface of the contact surface 10, and the precursor coating 11 is made of yttrium or bismuth which has been sintered to a high density in advance. It is made by pulverizing so-called ceramic-based high-temperature superconducting materials such as thallium-based and thallium-based materials.

In FIG. 2, 12 is a pressure cooker such as an autoclave, 13 is a pressure container of the pressure cooker 12, and 14 is a seal 7 for sealing the pressure container 13.
15 is a heater that heats the pressurized container 13; 16 is provided on the pressurized lid 14 to seal the pressurized container 13;
A pressurized gas introduction path 17 is provided in the pressurizing lid 14 to fill the inside with pressurized gas such as argon gas and a small amount of oxygen if necessary, and is provided in the pressurizing lid 14 to supply air, pressurized gas, etc. from inside the pressurizing container 13. 18 and 19 are valves provided in the pressurized gas introduction path 16 and the gas exhaust path 17; 20 is the divided container body 4;
．． This is a clamp for fixing the abutment surface 10 of No. 5.

Reference numeral 21 in FIG. 3 is a bolt that fastens between the contact surfaces 10 and 10 of the divided container body 4.5.

Next, the operation will be explained.

First, the precursor layer 11 is melted with a binder and applied in a layer on the entire inner surface of the divided container body 4.5 and the contact surface 10.
The divided container bodies 4 and 5 coated with 1 are overlapped at the abutting surfaces 10 and 10, and the abutting surfaces 10 and 10 are clamped together with 2.
Fixed at 0.

By melting the precursor layer 11 with a binder and applying it in a layer to the entire inner surface of the divided container body 4.5 and the mating surface of the contact surface 10.10, the layer of the precursor layer 11 can be made as thick as desired. be able to.

After that, the divided container bodies 4 and 5 in the above-mentioned combined state are put into the pressurized container 13 of the pressurized pot 12 and sealed with the pressurized lid 14,
A pressurized gas such as argon gas is introduced into the pressurized container 13 from the pressurized gas introduction path 16 to make the pressure inside the pressurized container 13 high.

At this time, if the precursor 11 needs to incorporate oxygen during sintering, it is also filled with a small amount of oxygen.

Then, the entire pressurized container 13 is rotated at 900° by the heater 15.
When heated to about C, the divided container body 4 inside the pressurized container 13
．． 5 is a sealed container 1 of high-temperature superconducting material in which the precursor layer 11 is sintered to form a high-temperature superconducting film 6, and the precursor layer 11 on the contact surface 10 and 10 is converted into an integrated high-temperature superconducting film 6.
is formed.

At this time, pressurized gas enters the integrated divided container body 4.5 from the through hole 7 formed in the divided container body 4.5, and the internal pressure of the divided container body 4.5 is also increased. During sintering, the high pressure closes the gaps between the precursor layers 11 after the binder has evaporated, so the formed high-temperature superconducting film 6 is densified, resulting in a high-temperature superconducting film with a high critical current density and a large film thickness. A sealed container 1 of high temperature superconducting material equipped with a membrane 6 is produced.

In this way, the high-temperature superconducting material sealed container 1 equipped with the dense and thick high-temperature superconducting film 6 can achieve high superconducting performance.

In addition, the high temperature superconducting material sealed container 1 made in this way has a contact surface 1
They are joined together by a high temperature superconducting film 6 of 0.10 mm, but if the high temperature superconducting material sealed container 1 requires great strength, the contact surfaces 10 and 10 may be fastened with bolts 21, or , the contact surfaces 10°10 are joined by brazing, laser welding, etc.

FIG. 4 shows a second embodiment of the present invention, which has the same configuration as the previous embodiment except that a container-shaped divided container body 22 and a lid-shaped divided container body 23 are used. Similar effects can be obtained.

FIG. 5 shows a third embodiment of the present invention, in which a divided container body 24, 25 has an insulating adhesive layer 26 made of a mixture of nickel, chromium, aluminum, yttrium, etc. formed on its inner surface by thermal spraying or the like. The configuration is the same as that of the previous embodiment except that .

In this way, by providing the insulating adhesive layer 26 between the divided container bodies 24 and 25 and the high temperature superconducting film 6, it is possible to obtain the same effects as in each of the above embodiments, and also to provide the divided container bodies 24 and 25. , 25 and the high-temperature superconducting film 6, and the superconducting performance can be improved.

Each of the embodiments described above is suitable when the divided container bodies 4, 5, 22, and 23 are made of ceramic, but this embodiment is suitable when the divided container bodies 24 and 25 are made of metal.

FIG. 6 shows another example of the method of sintering the precursor in a pressurized atmosphere according to the present invention, in which an autoclave (pressure cooker 12) capable of pressurizing up to about 300 atm is used instead of an autoclave (pressure cooker 12) capable of pressurizing up to about 300 atm.
This uses a HIP device 27 (hot isostatic press) that can pressurize up to approximately atmospheric pressure.

The HIP device 27 includes an outer cylindrical body 28 and an inner cylindrical body 29.
The upper end opening of the inner cylindrical body 29 is connected to the upper lid 3.
0, and the pressure booster piston 31 is movably fitted into the opening on the lower end side of the inner cylindrical shell 29.
A processing chamber 32 is formed inside the outer cylindrical body 28.
The lower end opening of the pressure increasing piston 31 is sealed with the lower cover 33.
A pressurizing chamber 34 is formed on the lower surface side of the , and after supplying pressurized gas to the inside of the processing chamber 32 with a low pressure pump 35, high pressure gas is supplied to the pressurizing chamber 34 with a high pressure pump 36 to operate the pressure increase piston 31. By doing so, the inside of the processing chamber 32 is made to have an extremely high pressure.

In the figure, 37 is a heater disposed inside the processing chamber 27, 38 is a check valve, and 39 is a relief valve.

When the HIP device 22 is used in this way, the same effects as in each of the above embodiments can be obtained, except that a denser high temperature superconducting film can be obtained compared to each of the above embodiments.

Note that the present invention is not limited to the above-described embodiments, and the contact surface is not limited to a flange, but may be a wave-like or chevron-like shape as long as the contact surface fits in a predetermined area. Of course, various changes can be made without departing from the spirit of the invention.

[Effects of the Invention] As explained above, according to the method for manufacturing a sealed container made of a high temperature superconducting material of the present invention, a sealed container made of a high temperature superconducting material provided with a high temperature superconducting film having a high density and a large film thickness can be produced in a simple process. can be obtained, and therefore an excellent effect can be achieved in that high superconducting performance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a side view of a sealed container in the first embodiment of the present invention, FIG. 2 is a side view of a pressure cooker for sintering the sealed container of FIG. 1, and FIG. A side view of a sealed container made of sintered high-temperature superconducting material, FIG. 4 is a side view of a sealed container in a second embodiment of the present invention, and FIG. 5 is a side view of a sealed container in a third embodiment of the present invention. Figure 6 is a side view of a hot isostatic press showing another example of the method of sintering the precursor in a pressurized atmosphere according to the present invention, and Figure 7 is a currently proposed high-temperature superconducting material. FIG. 2 is a side view showing a method for manufacturing a sealed container. In the figure, 4.5, 22, 23, 24.25 are divided container bodies, 7
10 is a through hole, 10 is a contact surface, 11 is a precursor plate, 12 is a pressure pot for sintering the precursor plate 11 in a pressurized atmosphere, and 27 is a HIP for sintering the precursor plate 11 in a pressurized atmosphere. Apparatus, A indicates a sealed container.

Claims (1)

[Claims] 1) Form contact surfaces that have a large contact area at the divided parts of the divided container bodies that have been formed in advance to constitute a sealed container so that they can come into contact with each other, and After applying the precursor powder of the high temperature superconducting material in a layered manner, the contact surfaces of each divided container body are brought into contact with each other to assemble the divided container bodies into one, and at least one portion of each divided container body is A method for manufacturing a sealed container made of a high-temperature superconducting material, which comprises forming a through hole and then sintering the combined divided container body and precursor powder in a pressurized atmosphere.