JP2003121590A - Aluminium-base complex material, production method therefor and complex product therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminium alloy base complex material which is light and superior in high-temperature strength and neutron absorption, its production method and complex products totally or partly, using the complex material for the member constituting the products. SOLUTION: The aluminium alloy base complex material is constituted of a matrix of aluminium alloy, ceramics body and neutron absorber materials. For the aluminium alloy base complex material is produced, by making aluminium alloy molten metal impregnated and coagulated in ceramics preform, and the complex material is used as constituting member of a complex product.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aluminum-based composite material, a method for producing the same, and a composite product using the same. In particular, the present invention is an aluminum-based composite material that is lightweight and has excellent high temperature strength and neutron absorption capacity.
In addition, composite products using this are structural members such as nuclear power related facilities and transport / storage containers for radioactive materials and shielding materials, and are used as baskets for storing spent nuclear fuel assemblies or spent nuclear fuel assemblies. The present invention relates to casks used for storage or transportation.

[0002]

2. Description of the Related Art Conventionally, since boron (B: boron) has a neutron-absorption capability, the structure of nuclear-related equipment such as a storage container for spent nuclear fuel that emits radiation such as neutrons is produced by boron-added stainless steel or aluminum alloy. It was used as a member. When an aluminum alloy containing boron is manufactured by melting and casting, as shown in FIG. 7, powdery metal boron is added to an aluminum alloy base metal (step S11), and it is melted and melted (step S11). The method of S12) and casting (step S13) was adopted.

Further, Japanese Patent No. 3207840 discloses that
A technique has been proposed in which an aluminum alloy powder to which boron is added is manufactured, and a molded body thereof is melted and cast to manufacture an aluminum alloy material. Furthermore, JP-A-10-3191
Japanese Patent Publication No. 83 also proposes a material in which boron fibers are compounded with a metal base to which boron is added.

[0004]

Since the above-mentioned boron-added stainless steel is heavy and has low thermal conductivity, when it is applied to a cask containing a high amount of fuel,
There is a problem that the heat generated from nuclear fuel is difficult to dissipate and a creep phenomenon occurs, which makes it unsuitable as a material for high storage. Further, the distribution of boron had the same problem as the boron-added aluminum alloy described below. Aluminum alloy is stainless steel,
It has a specific gravity of 1/3 and a thermal conductivity of 10 times, which is an advantage. However, in the conventional technology for producing an aluminum alloy containing boron by melting and casting, the specific gravity is increased in the molten aluminum alloy. , Various types of boron compounds are produced, and they precipitate or float.

Therefore, there is a problem in that the boron content of the obtained aluminum alloy is lower than the actual amount of boron added. In addition, most of the generated boron compounds have a size of about several hundreds of μm, and fine boron compounds agglomerate and coarsen, so that there is a problem that the uniformity of boron in the base material cannot be obtained. It was In an aluminum alloy to which boron is added, the boron content may become low as described above, or the boron distribution may become nonuniform, so that sufficient neutron absorption capacity may not be obtained. The AlB2 compound in an aluminum alloy casting is network-like, brittle, and poor in workability, so the content of boron is usually 1
It is as low as less than wt% and is 0.6 wt% for commercial use.

The aluminum alloy material described in the above-mentioned Japanese Patent No. 3207840 is manufactured by manufacturing an aluminum alloy powder to which boron is added and melting and casting the molded body. The aluminum alloy powder itself is small and boron is evenly distributed, but since the molded body is melted and cast thereafter, there is the above-mentioned problem, and the amount of boron contained in the base material is limited to 4 wt%. However, even with this amount, the distribution of boron in the base material may become non-uniform.

Further, the above-mentioned Japanese Patent Laid-Open No. 10-319183.
The technique proposed in Japanese Patent Publication has a problem that very expensive boron filaments are used, and there is a description of an Al-Mg-Si alloy (JIS6061 equivalent) containing 3% of boron, but this alloy is Since aluminum alloys for wrought materials have poor castability and are melted and cast, coarse Al-B compounds segregate at this boron content, resulting in non-uniform neutron absorption. Also, although it is described that short boron fibers can be used, since they are materials in which short fibers are dispersed in a metal matrix, they have a low high-temperature strength and pose a problem in practical use.

The present invention has been made in order to solve the above problems, and an object of the present invention is to provide an aluminum-based composite material which is lightweight and has excellent strength, particularly high temperature strength and neutron absorbing ability, and a method for producing the same. Another object of the present invention is to provide a composite product in which the aluminum-based composite material is used for all or part of the members constituting the product.

[0009]

As a result of earnest research, the inventors of the present invention have made a skeleton body by using a metal having a small specific gravity and a high thermal conductivity and good castability as a matrix and a material excellent in strength, particularly high temperature strength. As a result, the inventors of the present invention obtained the knowledge that it is effective to use a metal-based composite material composed of a neutron absorber and have reached the present invention.

That is, the aluminum-based composite material of the present invention is characterized by comprising an aluminum or aluminum alloy matrix, a ceramic skeleton body, and a neutron absorber. In the aluminum-based composite material of the present invention, it is preferable that the ceramic skeleton body and the neutron absorber are joined. The ceramic skeleton body is formed from a porous preform using whiskers of ceramics or short fibers. Furthermore, in the aluminum-based composite material of the present invention, the neutron absorber is a boron compound particle, and the aluminum alloy is Al-Si.
System, Al-Si-Mg system, Al-Si-Cu-Mg system,
It is preferable to use an Al-Si-Cu-Ni-Mg-based casting or an aluminum alloy for die casting. Furthermore, the ceramic skeleton body is preferably a sintered body of aluminum borate whiskers.

The ceramic skeleton body of the aluminum-based composite material in the present invention is a member that forms a composite material with a matrix of aluminum or an aluminum alloy and a neutron absorber and maintains strength. It is formed from a porous ceramics preform before impregnation.

The above aluminum-based composite material can be obtained by the following manufacturing method. That is, the method for producing an aluminum-based composite material of the present invention, a step of producing a porous ceramics preform bonded with a neutron absorber, a step of impregnating the porous ceramics preform with molten aluminum or aluminum alloy, and impregnated Solidifying the molten aluminum or aluminum alloy. In the production method of the present invention, preferably, the porous ceramic preform uses whiskers or short fibers of ceramics. The neutron absorber is preferably boron compound particles.

In the method for producing an aluminum-based composite material of the present invention, preferably, a slurry containing ceramic whiskers or short fibers and boron compound particles is prepared, and the slurry is dehydrated, pressurized, and then sintered. A porous preform is produced, and this porous preform is impregnated with a molten aluminum or aluminum alloy under high pressure and is cast and solidified to produce a composite material.

The present invention is further characterized in that all or a part of the members constituting the product are formed of an aluminum-based composite material composed of an aluminum or aluminum alloy matrix, a ceramic skeleton body and a neutron absorbing material. Providing body products. This composite product can be applied to a basket in which all the members constituting the product are aluminum-based composite materials, and further to a cask in which a part of the members constituting the product is an aluminum-based composite material. In this aluminum-based composite material, the ceramic skeleton is preferably a sintered body of aluminum borate whiskers, and the neutron absorber is preferably a boron compound particle.

In the present invention, whiskers or short fibers of ceramics are preferable as a reinforcing material for forming a porous ceramics preform because they have high strength and a simple manufacturing process can be applied, but the invention is not limited thereto. It may be produced by sintering using particles. For reinforcement whiskers and short fibers,
Although silicon carbide whiskers, alumina fibers, potassium titanate whiskers and the like can also be applied, aluminum borate whiskers have excellent mechanical properties at high temperatures as whiskers, and at the same time are industrially available at a low price. It is suitable as a reinforcing material for forming a preform that forms the skeleton of the base composite material.

Further, the type of ceramic of the reinforcing material may be an oxide type or a non-oxide type, and has the property of excellent thermal stability and high temperature strength at high temperature than aluminum or aluminum alloy which is the matrix of the composite material. The material may be any of the above materials, and this material may contain a substance having a neutron absorbing ability such as boron. Further, the reinforcing material forming the preform is not limited to the same material or the same shape, and may be a combination of different materials or different shapes.

In the present invention, the ceramic skeleton body and the neutron absorbing material may be joined together. Further, as the neutron absorbing material, in addition to boron and boron compounds such as boron carbide, boron nitride and boron oxide, those having a neutron absorbing ability such as gadolinium, gadolinium oxide, samarium and samarium oxide can be applied. In particular, boron carbide (B4
Boron carbide particles are preferable as C) because the content of boron, which has an excellent neutron absorption capability, is high, is stable up to a high temperature, and the industrial manufacturing method is established.

The neutron absorbing material can be used in the following manners.
Although not particularly limited, when using whiskers or short fibers as a reinforcing material, if neutron-absorbing particles having an average particle diameter larger than the diameter of these reinforcing materials are used, they are mixed with the reinforcing material forming the preform to form a slurry. It is preferable that the neutron absorbing particles are evenly distributed and bonded to the preform when the preform is produced by sintering. The neutron absorbing material may be combined with the ceramics preform and impregnated with a molten aluminum alloy serving as a matrix, and may also serve as a reinforcing material in the manufactured composite material.

The aluminum-based composite material of the present invention may contain 1 to 15 wt% of boron. The aluminum alloy is not particularly limited, but in consideration of castability, JIS AC1, 2, 3, 4, 5, 7, 8,
9 system and ADC system Al-Si system, Al-Si-Mg system,
Al-Si-Cu-Mg system, Al-Si-Cu-Ni-
Mg-based castings or die-casting alloys are preferable, and JIS AC4CH alloys, which are particularly excellent in castability, mechanical properties such as thermal conductivity and elongation, are preferable.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the aluminum-based composite material, the method for producing the same, and the composite product using the same according to the present invention will be described below in detail with reference to the accompanying drawings. The present invention is not limited to this embodiment.

FIG. 1 is a process chart showing an example of a method for producing an aluminum-based composite material according to the present invention. First, aluminum borate whiskers and boron carbide (B4C) particles that are boron compounds are mixed (step S21), and this mixture is mixed with water, an inorganic binder, or the like to form a slurry (step S22). The slurry is poured into a preform mold (step S23), and then dehydration / pressure molding (step S24) and sintering (step S25).
Then, a porous ceramics preform to which B4C particles are bonded is produced (step S26).

Next, the molten aluminum or aluminum alloy is pressurized and impregnated into the porous ceramic preform (step S27), and the impregnated molten aluminum or aluminum alloy is solidified to produce an aluminum-based composite material (step S28). To be done. The produced aluminum-based composite material is composed of a matrix of aluminum or an aluminum alloy, a ceramic skeleton which is a sintered body of aluminum borate whiskers, and boron carbide particles which is a neutron absorber.

A method of pressurizing and impregnating the above-mentioned molten aluminum or aluminum alloy into the porous ceramic preform (step S27) will be described with reference to FIG. First, the preform P obtained by sintering the whiskers is set in the mold D of the high-pressure casting machine (see FIG. 2).
Immediately after a)), aluminum or molten aluminum alloy Al is poured (FIG. 2b)). Then, it is a method of impregnating with an appropriate pressure (FIG. 2C) and solidifying under pressure within a short time. After solidification of aluminum or aluminum alloy Al, the preform P impregnated with aluminum alloy Al is taken out from the mold D (FIG. 2).
d)). The high-pressure casting method is an economical manufacturing method because it is easy to manufacture, mass producibility and partial compounding are possible.

The method of impregnating the molten aluminum or aluminum alloy into the porous ceramics preform is not limited to the above-mentioned high-pressure casting method, but includes a low-pressure casting method, a non-pressurizing casting method, and other molten metal impregnation. A known method such as a method may be used.

Next, a specific example of use of a composite product to which the aluminum-based composite material of the present invention is applied as a constituent member of the product will be described. FIG. 3 is a perspective view showing a cask using the aluminum-based composite material of the present invention as a part of the members constituting the product. FIG. 4 is a radial cross-sectional view of the cask shown in FIG. In this cask 100, the inner surface of the cavity 102 of the body 101 is machined to match the outer peripheral shape of the basket 130.

The body 101 and the bottom plate 104 are carbon steel forged products having a γ-ray shielding function. Note that stainless steel can be used instead of carbon steel. The body 101 and the bottom plate 104 are joined by welding. In addition, a metal gasket is provided between the primary lid 110 and the body 101 in order to ensure the sealing performance as a pressure-resistant container.

A resin 106, which is a polymer material containing a large amount of hydrogen and has a neutron shielding function, is filled between the body 101 and the outer cylinder 105. Also, the body 1
01 and the outer cylinder 105, a plurality of copper inner fins 107 for heat conduction are welded, and the resin 106
Is injected in a fluidized state into the space formed by the internal fins 107, and is cooled and solidified. In addition, it is preferable that the internal fins 107 are provided with high density in a portion having a large amount of heat in order to uniformly dissipate heat. In addition, between the resin 106 and the outer cylinder 105, a thermal expansion margin of several mm is required.
08 is provided.

The lid 109 includes a primary lid 110 and a secondary lid 11.
It is composed of 1. The primary lid 110 has a disc shape made of stainless steel or carbon steel that shields γ rays. The secondary lid 111 also has a disk shape made of stainless steel or carbon steel, and a resin 112 is enclosed as a neutron shield on the upper surface thereof. The primary lid 110 and the secondary lid 111 are attached to the body 101 by bolts 113 made of stainless steel or carbon steel.
Further, the primary lid 110 and the secondary lid 111 and the body 10
A metal gasket is provided between each of them and 1 to keep the internal sealing property. In addition, an auxiliary shield 115 enclosing the resin 114 is provided around the lid 109.

A trunnion 117 for suspending the cask 100 is provided on both sides of the cask body 116. Although the auxiliary shield 115 is shown in FIG. 3, the auxiliary shield 115 is removed and a buffer (not shown) is attached when the cask 100 is transported.
The cushioning body has a structure in which a cushioning material such as redwood material is incorporated in an outer cylinder (not shown) made of stainless steel.

The basket 130 is composed of, for example, 69 square pipes 132 which constitute a cell 131 for containing a spent nuclear fuel assembly. The aluminum pipe composite material of the present invention is used for the square pipe 132.

The number of cells in the cavity 102 is 5
Dummy pipes 133 are inserted on both sides of the square pipe row of 7 or 7. The dummy pipe 133 is intended to reduce the weight of the body 101, to make the body 101 uniform in thickness, and to securely fix the square pipe 132. This dummy pipe 133
Also, the aluminum-based composite material of the present invention is used, and the aluminum-based composite material is manufactured by the same steps as described above. In addition, this dummy pipe 133
Can be omitted.

The spent nuclear fuel assembly housed in the cask 100 contains fissile material and fission products,
Cask 1 because it generates radiation and decay heat
It is necessary to surely maintain the heat removal function, the shielding function and the criticality prevention function of 00 during the storage period (about 60 years). In the cask 100, the basket 13 in which the inside of the cavity 102 of the trunk body 101 is machined to form the square pipe 132
The outer side of 0 is inserted in a close contact state (without a large gap), and an internal fin 107 is provided between the body 101 and the outer cylinder 105. Therefore, the heat from the fuel rods is conducted to the body 101 through the square pipes 132 or the filled helium gas, and the heat is mainly transferred to the inner fins 10.
It will be discharged from the outer cylinder 105 through 7.

Γ generated from the spent nuclear fuel assembly
The wire is a body 10 made of carbon steel or stainless steel.
1, the outer cylinder 105, the lid 109 and the like are shielded.
Further, the neutrons are shielded by the resin 106 so that the radiation workers are not affected by the exposure. Specifically, the surface linear equivalent rate is 2 mSv / h or less,
It is designed to obtain a shielding function such that the dose equivalent rate of 1 m from the surface is 100 μSv / h or less. further,
Since the aluminum pipe composite material of the present invention is used for the square pipe 132 that constitutes the cell 131, it is possible to prevent neutrons from being absorbed and reaching criticality.

Further, according to the cask 100, the inside of the cavity 102 of the body 101 is machined so that the square pipe 132 forming the outer periphery of the basket 130 is inserted in a substantially tight contact state. The area facing 102 becomes wider, and the square pipe 132
The heat conduction from can be improved. Also, the cavity 102
Since the internal space area can be eliminated, the square pipe 13
If the two accommodated are the same, the body 101 can be made compact and lightweight. On the contrary, if the outer diameter of the body 101 is not changed, the number of cells can be secured accordingly,
The number of stored nuclear fuel assemblies can be increased.
Specifically, in the cask 100, the number of spent nuclear fuel assemblies that can be accommodated can be 69, and the outer diameter of the cask body 116 can be suppressed to 2560 mm and the weight can be suppressed to 120 tons.

FIG. 5 is a partial perspective view showing an example of the structure of a basket which is a composite product of the present invention in which the aluminum-based composite material of the present invention is applied to all the members constituting the product. The basket 130 is a basket divided body 13 in which a plurality of pipe materials 135 each having a substantially rectangular cross section and having a length of about 1 m, which are produced by a casting method, are bundled by bringing their outer surfaces into contact with each other.
6a, 136b, 136c, ..., And these basket divided bodies 136a, 136b, 136c ,.
It has a structure in which multiple stages are stacked and integrated. A method for binding the pipe members 135 may be appropriately selected from known methods such as welding, brazing, and fixing with screws or rivets via a connecting member.

In this basket 130, almost all of the members constituting the product are manufactured from the above-mentioned aluminum-based composite material of the present invention, so that the whole basket has a neutron absorbing ability. Since the basket 130 of the cask 100 has a high temperature of about 200 ° C. during use, high temperature strength is required.
The aluminum-based composite material of the present invention having a high temperature strength of MPa or more is practically useful.

In addition, as a composite product as an embodiment of the present invention, the aluminum-based composite material of the present invention is applied to the basket 130 which is a part of the component member of the product and all of the component members of the product. Although the example of the basket 130 configured by the applied square pipe 132 has been described, the present invention is not limited to these. It can be applied to racks of spent fuel pools, and its shape is square pipe 13
Besides 2, the plate-shaped member having slits can be applied to the basket 130 and the rack having the confectionery folding structure by engaging the slit portions alternately in the vertical and horizontal directions. Further, it is not limited to the structural member, it can also be applied as a plate-shaped shielding material that is used by pasting for shielding neutrons, and all or part of the members constituting the product are formed of the aluminum-based composite material of the present invention. The product is a composite product of the present invention, and is not limited to the products described above.

[0038]

EXAMPLE A concrete example of the aluminum-based composite material according to the above embodiment will be described. Aluminum borate whiskers having a diameter of 0.5 to 1.0 μm and a length of about 20 μm, and B4C particles of boron carbide having an average particle size larger than the diameter of the whiskers of about 8 μm are mixed with water and an inorganic binder to form a slurry. After that, it was poured into a preform molding die, dehydrated and pressurized to form a pre-sintered preform body having a predetermined volume ratio (volume ratio of whiskers forming the preform to the preform volume).

Next, a strong ceramic preform was produced by sintering at 1250 ° C. for 4 hours in an argon atmosphere. A JIS AC4CH alloy (composition is shown in Table 1) having excellent castability and mechanical properties was used as an aluminum alloy for impregnating a ceramics preform to form a matrix of a composite material. It should be noted that the ceramic preform needs to have a strength to withstand the impregnation resistance of the molten aluminum alloy serving as a matrix, and the compression strength was confirmed with a compression tester.

[0040]

[Table 1]

The ceramic preform was preheated to 500 ° C. in an argon atmosphere in a preheating furnace in advance. The preheated preform has a mold temperature of 35 on the high-pressure casting machine.
The composite material was manufactured by setting the mold in 0 ° C., immediately pouring the 750 ° C. AC4CH aluminum alloy melt, and lowering and pressing the plunger tip to impregnate and solidify the aluminum alloy melt in the ceramic preform. .
Pressing force, pressurizing speed, pressurizing holding time are 49MP each
a, 0.05 m / sec, 30 sec.

At this time, the volume ratio of the aluminum borate whiskers is set to 20%, and the volume ratio (Vf) of the B4C particles is set to 4.
% 4 and 8% preforms are made, and AC4CH
The aluminum-based composite material of the present invention was manufactured by impregnating the molten aluminum alloy. With respect to the aluminum-based composite material of the present invention, the states of the ceramic skeleton body, the neutron absorber and the matrix were observed with a macrostructure and with a scanning electron microscope. Similarly, the ceramic preform before being impregnated with the molten aluminum alloy serving as the matrix was also observed.

Regarding the preform of this example, aluminum borate whiskers were sintered to form a porous preform, and B4C particles as the neutron absorber were evenly distributed and bonded to the preform. It was observed that According to the observation of the aluminum-based composite material of the present invention, the porous ceramic skeleton body formed by sintering aluminum borate whiskers, the B4C particles bonded to the porous ceramic skeleton body, and the AC4CH aluminum alloy molten metal were added to the porous ceramic skeleton body. It was confirmed that they were impregnated to form a matrix.

Since the ceramics preform has the strength to withstand the impregnation and pressurization of the molten aluminum alloy serving as the matrix, in the aluminum-based composite material of the present invention, the shape of the porous ceramic skeleton is maintained, and B4
The C particles are bonded to this ceramic skeleton and are evenly distributed in the composite material.

FIG. 6 shows high temperature tensile properties as high temperature strength of the aluminum-based composite material of the present invention. The tensile test was performed using a test piece that was overaged by heat treatment at 350 ° C. for 100 hours in the atmosphere. A composite material can be produced even with a high boron content of 4% by volume of B4C and 8% by volume, and the neutron absorbing ability is excellent. The tensile strengths at room temperature are as high as 366 MPa and 373 MPa, respectively, but the high temperature tensile strength at 250 ° C. is 211% respectively due to the presence of the ceramic skeleton body in the composite material.
It has excellent characteristics such as MPa and 222 MPa.

In this embodiment, B4C is used as the neutron absorber.
The particles were added at 4% and 8% by volume, but aluminum borate whiskers containing boron as a reinforcing material forming the ceramic skeleton were added at 20% by volume.
Therefore, the total boron content in the aluminum-based composite material of the present invention is about 7 wt% and 10 wt%, respectively, and the boron content can be made higher than that of the conventional material, and the distribution of boron is uniform and the neutron absorbing ability is excellent. It is a material. In the composite material of the present invention, the amount of boron is 1 to 15 wt% in order to obtain the necessary neutron absorbing ability, and 4 to 10 wt% is preferable in order to obtain more excellent neutron absorbing ability.

According to the production method of the present invention, a ceramic preform impregnated with a molten aluminum alloy for forming a matrix of a composite material, instead of dissolving a substance having a neutron absorbing ability in the molten aluminum alloy, It can be added as a bonded neutron absorber. Therefore, the amount of addition can be made larger than in the conventional method, and at the same time, there is no problem that the compound of the neutron absorber and aluminum is precipitated in the form of a network or aggregated and segregated during casting, and can be uniformly distributed. 0 to 1 in the form of B4C particles
0 Vol% can be added.

The cask basket contains 200
Since the temperature rises to about 0 ° C., high temperature strength is required, and the aluminum-based composite material of the present invention having a high temperature strength of 200 MPa or more at 250 ° C. is useful. In this example, the sintering temperature is 1250 ° C. when the reinforcing material is aluminum borate whiskers, but the sintering temperature is preferably 1100 to 1400 ° C. The sintering temperature of the reinforcing material for forming the ceramics preform is not less than the temperature at which the preform after sintering is strong enough to withstand pressurization of molten aluminum alloy, etc. Although the strength of the reform increases, problems such as decomposition and oxidation of the constituents of the reinforcing material and neutron absorbing material will occur, so select at temperatures below the temperature at which these problems do not occur.

By applying the aluminum-based composite material of the present invention of the above-mentioned embodiment to all or a part of the members constituting the product, a composite product of a basket or cask which is lightweight and can be used at high temperature and has an excellent neutron absorbing ability. Was manufactured.

[0050]

As described above, according to the present invention, aluminum which is light in weight, has a high boron content, and has a uniform boron distribution, is excellent in neutron absorbing ability and is excellent in strength, particularly high temperature strength. A matrix composite material is obtained.
Further, it is possible to obtain a highly practical composite product such as a basket or a cask to which the aluminum-based composite material is applied.

[Brief description of drawings]

FIG. 1 is a process chart showing an example of a method for producing an aluminum-based composite material according to the present invention.

FIG. 2 is a diagram showing an example of a manufacturing method of impregnating a preform with a molten aluminum alloy.

FIG. 3 is a partial cross-sectional perspective view showing an example of the structure of the cask according to the present invention.

FIG. 4 is a radial cross-sectional view of the cask shown in FIG.

FIG. 5 is a partial perspective view showing an example of the structure of a basket according to the present invention.

FIG. 6 is a diagram showing material characteristics of an example of an aluminum-based composite material according to the present invention.

FIG. 7 is a process drawing showing a conventional method for manufacturing an aluminum alloy material.

[Explanation of symbols]

100 ... Cask, 101 ... Body, 109 ... Lid, 1
15 ... Auxiliary shield, 116 ... Cask body, 130 ... Basket, 131 ... Cell, 132 ... Square pipe, 133 ...
Dummy pipe, 135 ... Pipe material 136a to 136c ... Basket division body

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C22C 49/06 C22C 49/06 G21C 19/06 G21F 3/00 N G21F 3/00 G21C 19/06 S ( 72) Inventor Kazumi 1-1-1, Wadazaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries Ltd. Kobe Shipyard (72) Inventor Masashi Ishii 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo No. Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Toshihiro Matsuoka 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Prefecture Mitsubishi Heavy Industries Ltd., Kobe Shipyard (72) Inventor Kojima Yo Fukasawa-cho, Nagaoka-shi, Niigata Prefecture No. 1769 1 204, Fukasawa Town 2 (72) Inventor Shigeharu Kamachi 1769, Fukasawa Town, Nagaoka City, Niigata Prefecture 101 F Term of Fukasawa Town 2 (reference) 4K020 AA0 5 AC01 BB02 BB07

Claims (15)

[Claims] 1. An aluminum-based composite material comprising an aluminum or aluminum alloy matrix, a ceramic skeleton body, and a neutron absorber. 2. The aluminum-based composite material according to claim 1, wherein the ceramic skeleton body and the neutron absorbing material are bonded to each other. 3. The ceramic skeleton body is formed from a porous preform using whiskers or short fibers of ceramics before being impregnated with aluminum or an aluminum alloy serving as a matrix. The aluminum-based composite material according to claim 2. 4. The aluminum-based composite material according to claim 1, wherein the neutron absorber is composed of boron compound particles. 5. The aluminum alloy is Al--Si.
System, Al-Si-Mg system, Al-Si-Cu-Mg system,
The aluminum-based composite material according to any one of claims 1 to 4, which is an Al-Si-Cu-Ni-Mg-based casting or an aluminum alloy for die casting. 6. The aluminum-based composite material according to claim 1, wherein the ceramic skeleton body is a sintered body of aluminum borate whiskers. 7. A boron preform comprising a sintered body of aluminum borate whiskers to which boron carbide particles are bonded, and aluminum or an aluminum alloy impregnated in the porous preform. An aluminum-based composite material, wherein the boron content is 1 to 15 wt%. 8. A step of producing a porous ceramics preform bonded with a neutron absorber, a step of impregnating the porous ceramics preform with a molten aluminum or aluminum alloy melt, and solidifying the impregnated molten aluminum or aluminum alloy melt. And a step of manufacturing an aluminum-based composite material. 9. The method for manufacturing an aluminum-based composite material according to claim 8, wherein the porous ceramics preform uses whiskers or short fibers of ceramics. 10. The method for producing an aluminum-based composite material according to claim 8, wherein the neutron absorbing material is boron compound particles. 11. A step of producing a slurry containing a mixture of ceramic whiskers or short fibers and boron compound particles, a step of dehydrating / pressurizing the slurry, and a step of producing a porous preform by sintering. A method for producing an aluminum-based composite material, comprising: a step of impregnating the porous preform with an aluminum or aluminum alloy melt under high pressure; and a step of solidifying the impregnated aluminum or aluminum alloy melt. 12. A composite product, wherein all or part of members constituting the composite product are formed of an aluminum-based composite material composed of a matrix of aluminum or an aluminum alloy, a ceramic skeleton body, and a neutron absorbing material. Complex product to do. 13. The composite product according to claim 12, wherein the composite product is a basket containing a spent nuclear fuel assembly. 14. The composite product is a cask for storing or transporting a spent nuclear fuel assembly, and at least a part of its constituent members is a matrix of aluminum or aluminum alloy, a ceramic skeleton body and a neutron absorbing material. 13. A composite product according to claim 12, which is a structured aluminum-based composite material. 15. The ceramic skeleton body is a sintered body of aluminum borate whiskers, and the neutron absorbing material is a boron compound particle.
The composite product according to any one of 2 to 14.