JPH0987707A - Production of joined body of porous sintered metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a process for producing a joined body of porous sintered metallic bodies capable of producing porous sintered metallic bodies of various shapes while preventing the change in the structure of the joint parts as far as possible. SOLUTION: The joined body 1a of porous sintered metals in the process for producing joined body of the porous sintered metallic bodies to each other having a foamed structure obtd. by preparing, molding, drying and sintering of a foamable slurry contg. the metallic powder are obtd. by the first stage of superposing the dried planar moldings 2C, 2C on each other by parting their ends from each other, then forming a laminate having a stepped part at the ends, then sintering this laminate to integrate the moldings, thereby forming the stepped and sintered compacts 2D' and the second stage of joining the stepped parts of the stepped and sintered compacts 2D', 2D' with an adhesive, joining agent or by direct sintering without using these agents in the state of combining these stepped parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a porous sintered metal joined body, in which porous sintered metal bodies having a foamed structure are joined and assembled into a desired shape.

[0002]

2. Description of the Related Art The present inventors have developed a sponge-like porous sintered metal body having a foam structure obtained by preparing a foamable slurry containing metal powder, molding, drying and firing the foamable slurry. This porous sintered metal body is manufactured by sintering a dry molded body (green body) which is dried after molding, but the whole body shrinks by about 20% at the time of sintering and may be broken by the shrinkage. However, it is difficult to obtain a large-area flat plate-shaped one or a box-shaped three-dimensional one.

Therefore, there is a need for a technique for producing a porous metal plate having a size that does not break during sintering and joining the plates to obtain a desired large area and a three-dimensional shape. Conventionally, as a method of joining porous metal plates, for example, the end portions of another metal porous body sheet and another metal porous body sheet are overlapped with each other with a thermoplastic resin interposed therebetween, and the temperature is equal to or higher than the softening point of the thermoplastic resin. There is a method of pressing and compressing the polymerized portion of the sheet while heating (Japanese Patent Publication No. 61-6501).

There is also a method in which the end faces to be joined of two foam metal members to be joined are butted to each other, and molten metal is poured into the butted portions to join the foam metal members to each other (Japanese Patent Publication No. 4-68071). Gazette).

[0005]

However, in the former method, the density of the foam metal is doubled at the joint portion, the porosity at the joint portion becomes small, and the pore structure of the obtained joint body is reduced. Is non-uniform. In addition, the latter method also has a problem that the density at the joint changes and the structure becomes nonuniform at the joint. In both of these methods, the structure of the joint is different from that of the other parts, and the deterioration of the performance at the joint is unavoidable.

The present invention has been made in view of the above circumstances, and it is possible to manufacture porous sintered metal bodies of various shapes by bonding while preventing structural changes in the bonded portions as much as possible. An object of the present invention is to provide a method for producing a bonded metal joint.

[0007]

In order to achieve the above object, the present invention provides the following method for producing a porous sintered metal joined body. (1) A method for producing a joined body of porous sintered metal bodies having a foamed structure, which is obtained by preparing, molding, drying and firing a foamable slurry containing a metal powder, which is a dried plate-shaped body A first step of producing a stepped sintered body by stacking one another with the edges thereof separated from each other to form a laminated body having a step portion at the end, and then firing and integrating the laminated body. And a second step of joining the step portions of the stepped sintered bodies again by firing again in a state where the step portions of the stepped sintered bodies are combined with each other. A method for manufacturing a metal bonded body. (2) A method for producing a joined body of porous sintered metal bodies having a foamed structure, which is obtained by preparing, molding, drying and firing a foamable slurry containing a metal powder, which is a dried plate-shaped molded body A first step of producing a stepped sintered body by stacking one another with the edges thereof separated from each other to form a laminated body having a step portion at the end, and then firing and integrating the laminated body. And a second step of applying a slurry agent containing a metal powder and a water-soluble resin binder as a bonding agent to the surfaces to be bonded of the stepped portion of the stepped sintered body, followed by drying and firing. A method for producing a porous sintered metal joined body, which is characterized. (3) The method for producing a porous sintered metal joined body according to the above (2), wherein the slurry agent contains a foaming agent. (4) A method for producing a joined body of porous sintered metal bodies having a foamed structure, which is obtained by preparing, molding, drying and firing a foamable slurry containing a metal powder, which is a dried plate-shaped body A first step of producing a stepped sintered body by stacking one another with the edges thereof separated from each other to form a laminated body having a step portion at the end, and then firing and integrating the laminated body. And a second step of combining the stepped portions of the stepped sintered body with each other and joining the stepped portions of the stepped sintered body with an adhesive agent. Manufacturing method. (5) In the first step, a plurality of stepped sintered bodies having two or more different shapes are prepared, and in the second step, these stepped sintered bodies are combined and joined to each other to be assembled into a predetermined shape. The method for manufacturing a porous sintered metal joined body according to any one of (1) to (4).

According to the method for producing a porous sintered metal joined body of the present invention, when a dry formed body obtained by forming and drying a foamable slurry containing a metal powder is fired by bringing the dried formed bodies into close contact with each other, Utilizes the knowledge that these contact surfaces sinter, bond, and integrate, and that when the sintered metal bodies are contacted and fired again, the contact surfaces bond without an adhesive depending on the type of metal. To do.

That is, first, the dried plate-shaped compacts are overlapped with each other by shifting the edges thereof to form a laminated body having a stepped portion at the ends thereof, and then the laminated body is fired to be integrated. A sintered body is prepared (1st step), and the stepped sintered bodies prepared next are combined, joined by an adhesive or a bonding agent, or re-sintered to carry out step firing. The step portions of the joined bodies are joined (second step).

With this, since the step portions are combined with each other, the joint area is large and the joint strength is large. Further, by combining them, various shapes such as tiles, for example, a large-area plate-shaped body, a box-shaped three-dimensional shape, or the like can be formed. In this case, since the porosity and other physical properties of the bonded portion are not so different from those of the other portions, the entire porous sintered metal bonded body has substantially uniform porosity and other physical properties.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. As described above, the method for producing a porous sintered metal joined body of the present invention has the first step and the second step, and the first step is to make the dried plate-shaped formed bodies mutually end edges. After the layers are separated from each other and overlapped with each other to form a laminated body having a step portion at an end, the laminated body is fired and integrated to form a stepped sintered body.

First, the plate-shaped molded product can be obtained by preparing, molding, foaming and drying a foamable slurry containing a metal powder. The foamable slurry is prepared by, for example, preparing a slurry containing metal powder, a water-soluble resin binder (binder), a foaming agent, a surfactant, water and the like. Here, the type of metal powder is not limited, and for example, nickel, gold,
All sinterable metals and alloys such as silver, copper, iron, SUS, chromium, cobalt etc. can be used. The particle size of the metal powder is
The average particle size is preferably 500 μm or less, and particularly preferably 0.5 to 100 μm. If the average particle size is smaller than 0.5 μm,
Porosity may be reduced while mean particle size is 50
If it is larger than 0 μm, the strength of the resulting porous metal plate may be too weak. The blending amount of the metal powder in the slurry is preferably 5 to 80% (weight%, the same applies hereinafter), and particularly 30 to 80%.

The water-soluble resin binder functions as a binder to maintain the shape of the porous molded body when the slurry is dried. It also functions as a viscosity modifier for the slurry. Examples of the water-soluble resin binder include methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose ammonium, ethyl cellulose, polyvinyl alcohol and the like. The content of the water-soluble resin binder is preferably 0.5 to 20%, particularly preferably 2 to 10%. If the blending amount is less than 0.5%, the strength of the dry molded product may be weak, which may hinder handling.
If it is more than 20%, the viscosity may be too high and molding may be difficult.

The foaming agent is only required to be capable of generating gas to form bubbles, and a compound which decomposes at a constant temperature to generate gas and a volatile organic solvent can be selected. As a volatile organic solvent, for example, carbon number 5
8 hydrocarbon-based organic solvents. Such an organic solvent is a liquid at room temperature, is volatile, forms micelles in the slurry by the action of the surfactant, and vaporizes at room temperature or under heating to form fine bubbles. Carbon number 5
As the hydrocarbon-based organic solvent of ~ 8, for example, pentane,
Examples include neopentane, hexane, isohexane, isoheptane, benzene, octane, toluene and the like. The blending amount of the foaming agent is 0.05 to 10%, and particularly, 0.1.
The range of 5 to 5% is preferable. If the compounding amount is less than 0.05%, the generation of bubbles may be insufficient and the porosity may not increase, while if the compounding amount is more than 10%, the micelles will have a large diameter, and accordingly the molded body will be formed. Since the bubbles formed therein also have a large diameter, the strength of the obtained molded body and sintered body may decrease. Instead of using the foaming agent, the foamable slurry can be prepared by a method of vigorously mixing a gas such as air.

The surfactant has a function of stabilizing the foaming state and forming micelles of the foaming agent, and is alkylbenzene sulfonate, α-olefin sulfonate, alkyl sulfate ester salt, alkyl ether sulfate ester salt, alkane sulfone. Examples thereof include anionic surface active agents such as acid salts, nonionic surface active agents such as polyethylene glycol derivatives and polyhydric alcohol derivatives. The content of the surfactant is preferably 0.05 to 5%, particularly preferably 0.5 to 3%. If the amount is less than 0.05%, the formation of micelles may become unstable and it may be difficult to maintain fine bubbles, while if it is more than 5%, no further effect may be obtained. .

In addition to the above components, the foamable slurry according to the present invention may contain a plasticizer, a combustible agent for promoting pore formation, and the like. The plasticizer is for imparting plasticity to the molded product, and is a polyhydric alcohol such as ethylene glycol, polyethylene glycol, glycerin, sardine oil, rapeseed oil, oils and fats such as olive oil, ethers such as petroleum ether, diethyl phthalate, Examples thereof include diN-butyl phthalate, diethylhexyl phthalate, dioctyl phthalate, sorbitan monooleate, sorbitan trioleate, sorbitan palmitate and sorbitan stearate. The blending amount of the plasticizer is 0.
The range of 1 to 15%, especially 2 to 10% is preferable. If the amount is less than 0.1%, the plasticizing effect may be insufficient, whereas if it is more than 15%, the strength of the molded product may be insufficient.

Further, the combustible agent for promoting pore formation is for facilitating the formation of pores by eliminating it during the firing of the molded dried body. Therefore, it is possible to select a powder or fibrous material that retains its shape and disappears during firing. Specifically, the powdery material has a particle size of about 0.1 to 200 μm and a length of 200 μm or less, preferably 30 to 12
A fibrous material of about 0 μm is preferable. Examples of the material include pulp, cotton, lint, corn starch, carboxymethyl cellulose, water-insoluble cellulose fiber, polyvinyl butyral resin, polyvinyl resin, acrylic resin, polyethylene resin and the like.

The foamable slurry according to the present invention can be obtained by mixing the above components. In this case, the mixing order is not limited, but it is preferable to mix the foaming agent lastly in order to limit foaming as much as possible during mixing. Incidentally, when the slurry foams, the viscosity of the slurry decreases and the moldability deteriorates, but the time from the addition of the foaming agent to the foaming of the slurry is the type of the foaming agent, the addition amount,
The temperature and the temperature can be controlled, and the temperature can be controlled appropriately, and molding can be performed while the fluidity is maintained. Also, the viscosity of the slurry is 20000c at 20 ° C.
Range of ps to 70,000 cps, especially 30,000 to 5
A range of 5000 cps is preferred. If the viscosity is lower than 20000 cps, the foamed structure may collapse during drying, whereas if the viscosity is higher than 70,000 cps, the viscosity may be too high and molding may be difficult.

Next, the foamable slurry thus prepared is molded into a plate shape. The molding method is not particularly limited,
The doctor blade method is suitable. An outline of the doctor blade device is shown in FIG. This apparatus includes a first roll 20 around which the carrier sheet 10 is wound, and a second roll 21 around which the carrier sheet 10 sent out from this roll is wound, and conveys between the first roll 20 and the second roll 21. The carrier sheet 10 functions as if it were a belt conveyor. Then, from the first roll 20 side to the second roll 2
A slurry reservoir 30, a foaming zone 40, and a drying zone 50 are sequentially provided on the first side. The slurry reservoir 30 has a rectangular box shape in contact with the upper surface of the carrier sheet near the first roll 20, and the wall of the slurry reservoir 30 on the carrier sheet advancing direction side is separated from the carrier sheet with an adjustable gap. A doctor blade 60 is provided, and the thickness of the molded body is adjusted by the gap between the doctor blade 60 and the carrier sheet 10. When the prepared foamable slurry S is put into the slurry reservoir 30 and the carrier sheet 10 is conveyed, the foamable slurry S is extruded from the gap between the doctor blade 60 and the carrier sheet 10 and formed into a plate having a predetermined thickness. This plate-shaped molded body 2A is molded into a body 2A.
Are carried to the carrier sheet 10 and moved to the next foaming zone 40.

As a doctor blade 60, FIG.
It is preferable to use a double-blade blade as shown in FIG. This removes large bubbles from the gap between the two blades,
According to the knowledge that large bubbles do not enter the plate-shaped molded body extruded from the gap between the first blade and the carrier sheet, and that the thickness of the molded body can be made uniform regardless of the height of the foamable slurry. . In this case, the carrier sheet 10
The gap G1 between the edge of the first blade B1 on the downstream side and the carrier sheet is preferably larger than the gap G2 between the edge of the second blade B2 and the carrier sheet.
In addition, the gap D between the first blade B1 and the second blade B2
Is preferably about 5 to 20 mm, for example. Further, the gap G between the second blade B2 and the carrier sheet 10
2 is preferably in the range of 0.2 to 2 mm.

The foaming zone is formed before drying the molded body.
This is a step of sufficiently completing foaming. If you dry immediately after molding, the surface of the molded product will be dried first, and the skin will be in a state where the foaming inside the molded product and the evaporation of water are prevented,
Foaming may be uneven. For this reason, it is preferable to provide a foaming step between the molding step and the drying step.

When foaming is performed simultaneously with foaming, cracks are likely to occur on the surface of the molded article. Therefore, it is preferable to perform foaming in a high-humidity atmosphere in order to prevent drying as much as possible during foaming. Specifically, for example, the slurry viscosity is 35
When it is 000 cps or more, the humidity is 65% or more, preferably 80% or more. If the humidity is lower than 65%, cracks may be formed on the surface of the molded body during drying. Foaming temperature is 15
The range of ˜65 ° C., particularly 28˜40 ° C. is preferable. If the foaming temperature is lower than 15 ° C, foaming may take, for example, 2 hours or more, and if it exceeds 65 ° C, the molded body may foam too much and the molded body may collapse. Foaming time is usually 10-4
It is in the range of 5 minutes.

The foamed molded product 2B is conveyed to the drying zone 50 subsequent to the foaming zone 40, and is dried therein. The bubbles before drying are maintained by the presence of the water film. At this time, the slurry aggregates at the interface between the bubbles to form a skeleton structure (foam structure). If the water film breaks in this state, the slurry forming the skeleton will flow and the skeleton structure will collapse. A molded product having a foam structure can be obtained by drying so as not to cause such disintegration. Dry as quickly as possible so as not to cause collapse of the water film. Far infrared drying is suitable for this. Further, it is preferable to set the slurry composition such that the viscosity remarkably increases when the water in the slurry evaporates slightly.

As specific conditions for the drying step, for example, far-infrared rays may be used, and a heater temperature of 120 to 180 ° C., an ambient temperature of 40 to 80 ° C., and a drying time of 20 to 120 minutes may be adopted. As a result, a plate-shaped dry molded body 2C can be obtained. In the doctor blade device shown in FIG. 4, the carrier sheet 10 on which the molded body 2C after drying is placed
Is conveyed while being bent in a direction perpendicular to the lower side, so that the dry molded body (green body) 2C and the carrier sheet 10 are peeled off. Subsequently, the dried molded body 2C is cut into predetermined lengths by the cutter 70 and sent to the next firing step. In the description, an example in which the molding step, the foaming step, and the drying step are continuously performed has been described, but it goes without saying that separate devices may be used for these steps.

In the present invention, as shown in FIG. 1, a plate-shaped dry molded body (green body) thus obtained.
2C is cut into a predetermined shape and stacked to form a stepped laminate. The shape to be cut depends on the shape of the desired bonded body. For example, as shown in FIG. 1, when connecting the long side portions of the elongated green body 1C,
As shown in FIG. 2, when connecting in a right angle direction, or as shown in FIG. 3, two types of stepped sintered bodies are created, and these are combined like a mosaic and connected in the vertical and horizontal directions. In some cases, the cut shape of the dried molded body 1C is different.

Then, as shown in FIG. 1 (1), the cut green bodies 2C are overlapped with each other in the state in which step portions for obtaining a desired bonded body are formed and fired. By the firing step, as shown in FIG. 1 (2), the binders of the stacked green bodies are volatilized and sintered to form a porous layered metal body having a foamed structure, and the stacked green bodies are mutually bonded. It is possible to obtain a stepped sintered body 2D ′ in which the contact surfaces of No. 1 are joined and these are integrated.

The firing process is preferably a two-stage process. The first stage is called degreasing, which is a process for volatilizing organic substances, and the second stage is a process for sintering metal powder. Also, these steps can be continuous.
In the degreasing step, firing can be performed, for example, in an air atmosphere or a reducing gas atmosphere such as hydrogen gas at a temperature of about 300 to 700 ° C. for 10 to 60 minutes. In addition, the sintering process is performed in an ammonia decomposition gas atmosphere, a reducing atmosphere such as hydrogen gas, in a vacuum, or in an air atmosphere at a temperature of about 800 to 1400 ° C. for 20 to 120.
It can be baked for minutes. Since the volume shrinks by about 20% during degreasing and sintering, it is preferable to perform degreasing and sintering on a slippery bottom plate such as a graphite plate. After the sintering step, the thickness may be changed by skin pass rolling or the like.

In the present invention, as a second step, after the stepped sintered body 1D 'is obtained in this manner, as shown in FIG. Step parts are combined and joined to join the stepped sintered bodies. In this case, the compositions of the foaming slurries that are the raw materials are different from each other.
It is also possible to use one or more stepped sintered bodies. There are various methods for joining, for example, an adhesive, a method using a joining agent,
There is a method of baking the adhered portion of the sintered body without using these.

As a method of using an adhesive, there is a method of using a normal organic adhesive such as an acrylic adhesive, and as a method of using a bonding agent, a slurry agent containing a metal powder and a water-soluble resin binder is used. There are ways. The method using an organic adhesive can be performed according to a conventional method.

Here, the slurry agent used as the bonding agent will be described. This slurry agent contains a metal powder, a water-soluble organic binder, a surfactant and the like, and preferably contains a foaming agent and the like. Specifically, it is convenient to use the foamable slurry used for manufacturing the above-mentioned porous sintered metal body as it is as a bonding agent. In this case, the components and the preparation method can be the same as above. With this, since the bonding agent containing the same quality metal powder is used, the most effective sintering can be performed. Further, since the slurry penetrates into the porous sintered metal body due to the foaming agent and the metal powder does not have a high concentration on the joint surface, there is little possibility of changing the pore diameter of the joint surface.

As the metal powder blended in the slurry agent, a metal powder of a different type from the foaming slurry which is a raw material of the porous metal body may be used. For example, a metal that is more easily sintered can be selected. As the metal powder, the water-soluble organic binder, the surfactant, the foaming agent, and the like, those mentioned above can be exemplified, and the compounding amount is also the same.

Then, after applying the slurry agent as the above-mentioned joining agent to the step portion to be joined of the stepped sintered body,
As shown in (3), the step portions of the stepped sintered bodies are abutted on each other in a plane, and the surfaces of the step portions are brought into close contact with each other, and dried and baked. The firing conditions at this time can be the same as those for obtaining the stepped sintered body. By firing
The stepped portion coated with the bonding agent is sintered and bonded to obtain the porous sintered metal bonded body 1a of the present invention.

Further, in the case of directly joining without using an adhesive or the like, baking is performed with the stepped portions abutting each other. The baking conditions can be the same as the sintering conditions for obtaining the stepped sintered body. In this case, for example, gold, silver, copper, iron, SUS, chromium, cobalt or the like is suitable as the metal constituting the porous sintered metal.

As shown in FIG. 2, the stepped sintered bodies 2D 'may be combined in a direction perpendicular to each other, whereby a three-dimensional porous sintered metal bonded body 1b can be manufactured. . Also, as shown in FIG.
A stepped sintered body 2D '(A) and 2D' (B) are prepared, and these are combined like a tile to obtain a large area porous sintered metal bonded body 1C with no limitation on the obtained area. Can be obtained.

[0035]

【Example】

[Example 1] A foamable slurry was prepared with the components and the blending amounts (% by weight) shown in Table 1.

[0036]

[Table 1] The prepared foamable slurry was molded into a thickness of 1 mm by using a doctor blade method, and then was held in a thermo-hygrostat having a humidity of 90% and a temperature of 40 ° C. for 15 minutes for foaming. afterwards,
A green body was produced by holding in an air circulation type far-infrared dryer having a heater temperature of 160 ° C. and an ambient temperature of 40 ° C. for 1 hour and drying. At this time, the green body swelled in the above-mentioned foaming process, and its thickness was about 5 times the molding thickness. The obtained green body is cut out, and the obtained green bodies are stacked and arranged so as to have the shapes shown in FIGS. 3 (A) and 3 (B), placed on a graphite plate, and heated to a temperature of 38 in air.
It was degreased (debinding) by holding at 0 ° C for 1 hour. Next, in an atmosphere of decomposed gas of ammonia gas, the temperature was maintained at 1000 ° C. for 1 hour for sintering, and the stepped sintered bodies 2D ′ (A) and 2D ′ shown in FIGS. 3 (A-1) and (A-2) were used. (B) was obtained.
The thickness of the sintered body was 4.1 mm on average in the non-overlapping portion. Further, the green body contracted isotropically by 19% in length due to the sintering.

Then, an acrylic resin adhesive is thinly applied to the stepped portion of the stepped sintered body to form a stepped sintered body 2D '(A).
And 2D ′ (B) were butted against each other and bonded as shown in FIG. 3 (C) to manufacture a large area porous sintered metal bonded body 1C. [Example 2] A stepped sintered body was prepared in the same manner as in Example 1,
These are also combined as shown in FIG. 3 (C), and the whole is kept at a temperature of 1000 ° C. for 1 hour in an atmosphere of N ₂ -5% H ₂ to burn the stepped portion, thereby forming a large-area porous sintered metal. A bonded body 1C was manufactured.

[0038]

EFFECTS OF THE INVENTION According to the method for producing a porous sintered metal body of the present invention, a porous sintered metal joined body having various shapes can be easily produced using a porous sintered metal plate having a foam structure. be able to.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view illustrating an example of a manufacturing method of the present invention.

FIG. 2 is a schematic cross-sectional view showing another example of a method of combining stepped sintered bodies in the manufacturing method of the present invention.

FIG. 3 is a schematic cross-sectional view showing still another example of a method of combining stepped sintered bodies in the manufacturing method of the present invention.

FIG. 4 is a sectional view showing an outline of a doctor blade device.

FIG. 5 is a schematic sectional view showing a doctor blade having two blades.

[Explanation of symbols]

 2A molded body 2B foamed body 2C dry molded body 2D 'stepped sintered body 1a, 1b, 1c porous sintered metal bonded body

Claims (5)

[Claims] 1. A method for producing a joined body of porous sintered metal bodies having a foamed structure, which is obtained by preparing, molding, drying and firing a foamable slurry containing a metal powder, which is a dried plate-like material. Forming a stepped sintered body by stacking the molded bodies with their edges separated from each other to form a laminated body having stepped portions at the ends, and then firing and integrating the laminated body. Porous, characterized in that it has one step and a second step of joining the step portions of the stepped sintered bodies together by firing again in a state of combining the step portions of the stepped sintered bodies. A method for manufacturing a sintered metal joined body. 2. A method for producing a joined body of porous sintered metal bodies having a foamed structure, which is obtained by preparing, molding, drying and firing a foamable slurry containing a metal powder, which is a dried plate-like material. Forming a stepped sintered body by stacking the molded bodies with their edges separated from each other to form a laminated body having stepped portions at the ends, and then firing and integrating the laminated body. It has one step and a second step of applying a slurry agent containing a metal powder and a water-soluble resin binder as a joining agent to the surfaces to be joined of the step portion of the stepped sintered body, and then drying and firing. A method for producing a porous sintered metal joined body, comprising: 3. The method for producing a porous sintered metal joined body according to claim 2, wherein the slurry agent contains a foaming agent. 4. A method for producing a joined body of porous sintered metal bodies having a foamed structure, which is obtained by preparing, molding, drying and firing a foamable slurry containing a metal powder, which is a dry plate-like shape. Forming a stepped sintered body by stacking the molded bodies with their edges separated from each other to form a laminated body having stepped portions at the ends, and then firing and integrating the laminated body. Porous sintered metal comprising one step and a second step of combining the step portions of the stepped sintered body with each other and joining the stepped portions of the stepped sintered body to each other with an adhesive. Method for manufacturing joined body. 5. A plurality of stepped sintered bodies having different shapes are formed in the first step, and these stepped sintered bodies are combined and joined in a second step to obtain a predetermined shape. The method for manufacturing a porous sintered metal joined body according to claim 1, which is assembled.