JP2019210492A - Method for producing aluminum-based slurry adhered body and method for producing aluminum-based porous body - Google Patents

Abstract

To provide a method for producing aluminum-based slurry adhered body, in which, when producing aluminum-based slurry adhered body, the amount of slurry used is reduced.SOLUTION: Provided is a method for producing aluminum-based slurry adhered body, in which, to a resin foam that has a three-dimensionally connecting skeleton and in which, by said skeleton, three-dimensionally communicating pores are formed, and in a state in which the resin foam is compressed, an aluminum-based slurry containing aluminum powder and/or aluminum alloy powder is pressed in, to adhere aluminum-based slurry to this resin foam.SELECTED DRAWING: Figure 1

Description

  One embodiment of the present invention relates to a method for producing an aluminum-based slurry adhering body and a method for producing an aluminum-based porous body.

  A porous metal body having a three-dimensional network structure having a three-dimensionally connected skeleton and three-dimensional communication holes formed by the skeleton is formed on a resin foam having a communication hole and an organic polymer binder. After coating the mixture with metal powder by dipping, spraying, etc., it is heated to decompose and remove the resin foam and to sinter the metal powder (Patent Documents 1 to 3), or a three-dimensional network structure After the surface of the skeleton is imparted with adhesiveness and powder is adhered, it is manufactured by a method of heating to decompose and remove the three-dimensional network structure and sintering the powder (Patent Document 4).

Moreover, since the porous body which has a three-dimensional network structure has a large contact area with a fluid, application to the heat exchange component of a heat exchanger is examined (patent document 5).
A heat exchanger is a device that is used for heating and cooling by efficiently transferring heat from a high-temperature object to a low-temperature object. In general, a fluid such as a liquid or a gas is used as a heat exchange medium. Heating or cooling is performed by applying heat to the fluid (heating) or removing heat from the fluid (cooling). In such a heat exchanger, the heat exchange efficiency is increased by increasing the contact area with the fluid by providing fins or the like made of a metal material having high thermal conductivity on the heat transfer member. If a porous body having a three-dimensional network structure made of a metal material having a high thermal conductivity is used instead of the fins and the fluid is passed through the communicating pores, the metal material having a high thermal conductivity and the fluid It is considered that the efficiency of heat exchange can be further increased because the contact area with can be further increased.

JP 05-339605 A Japanese Patent Laid-Open No. 08-020831 Japanese Patent Publication No. 61-053417 Japanese Patent Laid-Open No. 06-235033 Japanese Patent Publication No. 06-089376

In the conventional method, when producing a porous body having a three-dimensional network structure, a slurry containing metal powder is adhered to a resin foam, and then excess slurry is removed using a roll, a press, a centrifugal separator, or the like. Then, after obtaining the slurry adhering body on which the required amount of slurry is adhered, the slurry adhering body is dried and fired. This method has a problem of increasing the amount of slurry used. Further, there is a problem that the number of steps increases in order to collect and reuse the removed slurry.
Further, when the metal powder is attached to the resin foam in the form of spray or powder, there is a problem that it is difficult to uniformly attach the metal powder to the inside of the resin foam.

  One object of one embodiment is to reduce the amount of slurry used when producing an aluminum-based slurry adhering body, and to uniformly adhere the slurry to the resin foam.

One embodiment is summarized as follows.
[1] Aluminum powder and / or aluminum alloy powder in a state in which the resin foam is compressed into a resin foam having a skeleton that is three-dimensionally connected and having pores that communicate with the skeleton in a three-dimensional manner. The manufacturing method of the aluminum-type slurry adhesion body which press-fits the aluminum-type slurry containing and adheres the said aluminum-type slurry to the said resin foam.
[2] The method for producing an aluminum-based slurry adherend according to [1], wherein the porosity of the resin foam is 90% to 99%.
[3] The method for producing an aluminum-based slurry adherend according to [1] or [2], wherein an average particle diameter of the aluminum powder and / or the aluminum alloy powder is 1 μm to 50 μm.
[4] An aluminum-based slurry adherent is produced according to the method for producing an aluminum-based slurry adherent according to any one of [1] to [3], and the resin foam is removed by heating the aluminum-based slurry adherent. The manufacturing method of an aluminum-type porous body.

  According to one embodiment, when the aluminum-based slurry adhering body is produced, the amount of the slurry used can be reduced, and the slurry can be uniformly adhered to the resin foam.

It is a schematic sectional drawing of the press apparatus by one Embodiment.

As a method for producing an aluminum-based slurry adhering body according to an embodiment, a resin foam having a skeleton that is three-dimensionally connected and in which pores that are three-dimensionally connected by the skeleton are formed is compressed. The aluminum-based slurry containing aluminum powder and / or aluminum alloy powder is press-fitted, and the aluminum-based slurry is adhered to the resin foam.
According to this, when producing an aluminum-based slurry adhering body, the amount of slurry used can be reduced, and the slurry can be uniformly adhered to the resin foam.
Hereinafter, the aluminum powder and / or the aluminum alloy powder are collectively referred to as an Al-based powder. The aluminum-based slurry is also referred to as Al-based slurry.

By pressing the slurry into the resin foam in a state in which the resin foam is compressed, the volume of the resin foam is reduced, and the slurry is easily spread over the entire resin foam when the slurry is pressed. As a result, the amount of slurry used can be reduced, and the slurry can be uniformly adhered over the entire resin foam.
Further, by reducing the amount of slurry used, excess slurry can be reduced after the slurry is pressed into the resin foam. For example, by using an appropriate amount of slurry when pressing the slurry into the resin foam, a mechanism for removing and collecting excess slurry can be eliminated, and a mechanism for reusing the slurry is also unnecessary. Can do.
In addition, since it is possible to eliminate the step of pressing the slurry into the compressed resin foam and then removing the excess slurry, the slurry can be uniformly adhered to the vicinity of the side surface of the resin foam. Even when the slurry is pressed into the compressed resin foam and then the resin foam is restored, the slurry can be uniformly attached in the vicinity of the side surface of the resin foam.

As the resin foam, a three-dimensional network structure having a skeleton that is three-dimensionally connected and having pores communicating in a three-dimensional manner can be used. The appearance shape, pore physical properties, and the like of the resin foam can be appropriately set according to the final shape of the slurry adhering body.
This resin foam is supported by adhering an Al-based powder to the surface of the skeleton, and the Al-based powder serves as a mold material for forming a three-dimensional structure. Examples of the resin foam include foamed resins such as polyurethane resin, silicone resin, and polyester resin. Among them, polyurethane foam is preferable. In the case where the aluminum foam is obtained by removing the resin foam from the slurry adherent, it is preferable that the resin foam has a property of being removed by thermal decomposition.

For example, the resin foam preferably has an overall porosity of 90% to 99%, more preferably 95% to 98%.
The size of the pores contained in the resin foam is preferably 500 μm to 4000 μm, more preferably 1000 μm to 3500 μm. Here, the size of the communication hole is an equivalent circle diameter.

The aluminum-based slurry contains aluminum powder and / or aluminum alloy powder. The solvent of the Al-based slurry may be aqueous or non-aqueous. However, since the solvent can be removed easily and safely, alcohol, water, a phenol resin, or the like can be used, and water is particularly preferable. The concentration of the Al-based powder with respect to the entire Al-based slurry is preferably 20% by mass to 70% by mass, and more preferably 30% by mass to 60% by mass. The Al-based slurry may further contain additives such as a binder, an organic phosphorus compound, an antifoaming agent, and a dispersing agent.
The viscosity of the Al-based slurry is preferably 20 to 2000 mPa · s, more preferably 50 to 1000 mPa · s when measured at 50 rpm with an E-type viscometer.

As the aluminum powder, Al: 95% by mass or more, and the balance may be aluminum powder made of impurities such as C, N, and O. A porous body excellent in heat exchange can be obtained by heat-treating the slurry adhering body using aluminum having a high thermal conductivity to produce an aluminum-based porous body.
As the aluminum alloy powder, aluminum alloy powder obtained by previously alloying Al with an alloying element such as Cu, Mn, Mg, or Si can be used. By using the aluminum alloy powder to heat-treat the slurry adhering body to produce an aluminum-based porous body, the skeleton is formed of an aluminum alloy, and a porous body with higher strength can be obtained.
The Al-based slurry may contain one kind of aluminum powder and aluminum alloy powder alone, or may contain two or more kinds mixed.
In addition, by adding alloying elements such as Cu, Mn, Mg, and Si to aluminum, the thermal conductivity is lower than in the case of aluminum alone, but the base metal is Al, so the heat conductivity is sufficiently high. Can be maintained.
As the Al-based powder, a general product having an oxide film (alumina: Al ₂ O ₃ ) of about 10 mm on the surface can be used.

The average particle diameter of the aluminum powder and / or aluminum alloy powder is preferably 1 μm to 50 μm. When two or more kinds of aluminum powder and aluminum alloy powder are used in combination, at least one average particle diameter is preferably in the above range, and all average particle diameters are more preferably in the above range.
The Al-based powder is preferably fine so as to adhere closely to the fine resin skeleton surface of the resin foam. When the Al-based powder becomes larger, it becomes difficult to adhere closely to the resin skeleton surface of the resin foam, and due to the increase in the mass of the Al-based powder, it becomes difficult to adhere to the resin skeleton surface of the resin foam and falls off. It becomes easy. From this viewpoint, the average particle diameter of the Al-based powder is preferably 50 μm or less. Furthermore, the Al-based powder preferably has an average particle diameter of 50 μm or less and does not contain powder having a particle diameter exceeding 100 μm.
Since aluminum is an active metal, too fine powders are difficult to handle. From this viewpoint, the average particle diameter of the Al-based powder is preferably 1 μm or more.
Here, the average particle diameter can be measured by a laser diffraction method.

A binder such as an organic polymer binder can be further added to the Al-based slurry.
Examples of the organic polymer binder include polyvinyl alcohol resin, polyacrylic resin, and water-soluble cellulose.
For example, the Al-based slurry is preferably prepared by adding an Al-based powder to a polyvinyl alcohol aqueous solution in which a polyvinyl alcohol resin is dissolved in water. The concentration of the polyvinyl alcohol content in the aqueous polyvinyl alcohol solution is not particularly limited, and is preferably such that the Al-based powder easily adheres to the resin foam and has a slurry viscosity that is easy to handle.
A binder can be mix | blended by 0.2 mass%-3 mass% with respect to Al type slurry whole quantity.

An organophosphorus compound can be further added to the Al-based slurry. As the organic phosphorus compound, an organic phosphorus compound that is chemically bonded to the Al-based powder can be preferably used.
As the organic phosphorus compound, for example, a phosphate ester, a polymer containing phosphorus, or the like can be preferably used. Examples of phosphoric acid esters include aliphatic phosphoric acid monoesters; aromatic phosphoric acid monoesters; polyoxyethylene alkylphenolic acids, epoxy compounds, or phosphoric acid esters obtained by reacting acrylic compounds with phosphoric acid; or derivatives thereof Can do.
As the organic phosphorus compound, an aliphatic phosphate monoester having 10 to 18 carbon atoms represented by the following formula can be preferably used. In the following formula, R is a saturated hydrocarbon group having 10 to 18 carbon atoms.
Aliphatic phosphate monoester: R—O—PO (OH) ₂

Specific examples of the phosphate ester include isopropyl acid phosphate, butyl acid phosphate, hexyl acid phosphate, octyl acid phosphate, 2-ethylhexyl acid phosphate, nonyl acid phosphate, decyl acid phosphate, dodecyl acid phosphate, tridecyl acid phosphate, Aliphatic phosphate monoesters such as isotridecyl acid phosphate, tetradecyl acid phosphate, hexadecyl acid phosphate, stearyl acid phosphate; aliphatic phosphate monoesters having an alkoxy group such as butoxyethyl acid phosphate and butoxyethoxyethyl acid phosphate ; Phenyl acid phosphate, propyl phenyl acid phosphate Eto, and aromatic phosphoric acid monoesters such as butyl phenyl acid phosphate, and the like.
The above-mentioned organic phosphorus compounds can be used alone or in combination of two or more.
An organophosphorus compound can be mix | blended with 0.2 mass%-10 mass% with respect to Al type slurry whole quantity.

Next, an adhesion process for adhering the Al-based slurry to the resin foam will be described. As the resin foam and the Al-based slurry, those described above can be used.
First, the resin foam is compressed. The method for compressing the resin foam is not particularly limited, and it is preferable to compress the resin foam by applying a load to the resin foam using a press device that can uniformly compress the whole. The direction of compressing the resin foam may be from one direction or from two or more directions, but it is preferable to compress from one direction of the resin foam.
The resin foam is preferably compressed to 30% or less with respect to the original thickness in the compression direction, more preferably 20% or less, and even more preferably 10% or less. By reducing the thickness of the resin foam in a compressed state, the Al-based slurry can easily spread throughout the resin foam.
For example, a resin foam can be arranged between a pair of plates, and the resin foam can be compressed by applying a load to the resin foam from one or both of the pair of plates.
In FIG. 1, the cross-sectional schematic diagram of the press apparatus by one Embodiment is shown.
The press apparatus 10 shown in FIG. 1 includes compression jigs 1a and 1b that are a pair of plates. Between the pair of compression jigs, the resin foam 2 is disposed in a compressed state.

Next, the slurry is pressed into the resin foam. Thereby, a slurry deposit can be obtained. The press-fitting method is not particularly limited, and the slurry may be press-fitted into the compressed resin foam from one or both of the compression directions, or the slurry may be press-fitted from one or both of the directions orthogonal to the compression direction, These may be combined.
For example, in a configuration in which a resin foam is disposed between a pair of plates and the resin foam is compressed by applying a load to one or both of the pair of plates, the one or both of the pair of plates penetrates in the compression direction. A nozzle is provided, and the slurry can be pressed into the resin foam through this nozzle. One or two or more nozzles may be provided on one plate. In order to spread the slurry more uniformly on the resin foam, a configuration in which one nozzle is provided at a central portion of the plate or a configuration in which a plurality of nozzles are arranged at equal intervals on the plate surface is preferable.
In the press apparatus 10 shown in FIG. 1, the nozzle 3 is formed in the center part of one compression jig 1a among a pair of compression jigs.

  Moreover, in the structure which arrange | positions resin foam between a pair of plates, the side surface of the direction orthogonal to the compression direction of the resin foam may be sealed, and one part or the whole may be open | released. In the configuration where the side surface of the resin foam is sealed, when the slurry is press-fitted into the resin foam through the nozzle, the press-fitting is stopped when the load increases to some extent, so that an appropriate amount of the slurry is spread over the entire resin foam. be able to. In a configuration in which the side surface of the resin foam is partially or entirely open, when pressing the slurry into the resin foam through the nozzle, the press-fitting is stopped to the extent that the slurry does not spill from the open portion, so that an appropriate amount can be obtained. The slurry can be spread throughout the resin foam.

  The pressure when the slurry is press-fitted into the resin foam is not particularly limited, and may be appropriately set according to the size of the resin foam, the porosity, the viscosity of the slurry, the diameter of the nozzle, the load during compression, etc. It is preferable that the pressure is such that the slurry spreads over the entire resin foam.

The compressed slurry adhering body can be restored to the original shape of the resin foam by releasing the load. Thereby, a slurry adhering body in which an Al-based slurry adheres to the surface of the resin foam skeleton can be obtained.
Thereafter, it is preferable to dry the slurry deposit. Thereby, volatile components such as a solvent can be removed from the slurry adhering to the skeleton surface of the resin foam. The drying temperature is not particularly limited and is preferably equal to or higher than the temperature at which the volatile component volatilizes or evaporates, and is preferably equal to or lower than the temperature at which the resin foam is not thermally decomposed.

According to the method for producing an aluminum-based slurry adhering body described above, an aluminum-based slurry adhering body having a three-dimensional network structure in which three-dimensionally connected skeletons are formed and pores communicating in three dimensions are formed by the skeleton. Can be obtained.
The aluminum-based slurry adhering body can be produced so as to have a desired shape and size according to the shape and size of the resin foam, and is desired according to the pore properties such as the porosity and pore size of the resin foam. It can produce so that it may become the pore physical property.

The aluminum-based slurry adhering body obtained as described above can be used as it is. Moreover, an aluminum-type porous body can be produced using the aluminum-based slurry adhering body obtained as described above.
As an aluminum-based porous body manufacturing method according to an embodiment, an aluminum-based slurry adherent is produced according to the above-described aluminum-based slurry adherend manufacturing method, and the aluminum-based slurry adherent is heated to remove the resin foam. It is characterized by.

The slurry adhering body is preferably heat-treated at a temperature equal to or higher than the temperature at which the resin foam is thermally decomposed. As a result, the resin skeleton can be removed, leaving a hollow skeleton formed of metal.
Moreover, it is preferable to heat-process a slurry adhering body more than melting | fusing point of Al type powder. For example, it is higher than the melting point of aluminum (660.4 ° C.). As a result, the Al-based powder adhered to the resin foam can be melted to form a denser skeleton.

  The surface of the Al-based powder adhering to the resin foam is covered with an oxide film before the heat treatment, and the respective particles are in contact with each other through the oxide film. When the Al-based powder attached to the resin foam is heat-treated at a temperature equal to or higher than its melting point, it melts and breaks the oxide film on the surface of the particles so that adjacent particles are bonded while wetting the particle surface. At this time, the oxide film formed on the particle surface becomes a substitute skeleton, and the molten Al-based powder wets outside the substitute skeleton, so that the particles are more firmly bonded to each other while maintaining the shape of the outer wall of the skeleton. It becomes like this.

Specifically, the slurry adhering body is preferably heat-treated at 660 ° C. or higher, more preferably 665 ° C. or higher.
Although a slurry adhesion body is not limited to this, It is preferable to heat-process at 700 degrees C or less, and 695 degrees C or less is more preferable.
The slurry adherent is preferably heat-treated in a non-oxidizing atmosphere. As a result, oxidation of the Al-based powder can be prevented and thermal decomposition of the resin foam can be promoted.

According to the above-described method for producing an aluminum-based porous body, a hollow skeleton formed of aluminum and / or an aluminum alloy can be formed. The skeleton after the heat treatment has a hollow shape in which the portion where the resin skeleton was present becomes a hollow portion.
Depending on the manufacturing conditions, an oxide film formed on the raw material particle surface, that is, alumina (Al ₂ O ₃ ) is dispersed in the aluminum and / or aluminum alloy forming the skeleton of the aluminum-based porous body. become.
Since alumina is a hard material, it can be dispersed in the base aluminum and / or aluminum alloy to strengthen the base. The strength of the skeleton can be further increased by dispersing alumina in the skeleton of the porous body.

According to the method for producing an aluminum-based porous body described above, an aluminum-based porous body having a skeleton that is three-dimensionally connected and having a three-dimensional network structure in which pores communicating in a three-dimensional manner are formed by the skeleton. Can be obtained.
The overall porosity of the aluminum-based porous body is preferably 90% to 99%, more preferably 95% to 98%. Here, the porosity of the entire porous body is obtained by measuring the mass, length, width, and height to determine the apparent density, and dividing by the theoretical density of aluminum or aluminum alloy to determine the density ratio (%). This density ratio can be subtracted from
The size of the pores contained in the aluminum-based porous body is preferably 500 μm to 4000 μm, and more preferably 1000 μm to 3500 μm. Here, the size of the communication hole is an equivalent circle diameter.
The specific surface area of the aluminum-based porous body is preferably from 500~3000m ^-1, 550~1250m ^-1 are more preferred. Thereby, ventilation resistance and heat dissipation can be further improved. Here, the specific surface area of the aluminum-based porous body can be measured by a gas adsorption method.

The skeleton of the aluminum-based porous body is preferably aluminum and / or an aluminum alloy having a density ratio of 90% or more, particularly 95% or more. This density ratio is the ratio of the density of the skeleton formed by aluminum and / or aluminum alloy to the theoretical density of aluminum and / or aluminum alloy.
The aluminum-based porous body preferably has a hollow skeleton. The outer diameter of the skeleton is preferably 0.1 to 0.3 mm. The inner diameter of the skeleton is preferably 0.04 to 0.3 mm. The thickness in the cross-sectional direction of the outer wall of the skeleton is preferably 0.03 to 0.2 mm.

(Example 1)
As the resin foam, a polyurethane foam having a thickness of 25 mm (trade name Everlight SF, manufactured by Bridgestone Corporation) was prepared. This polyurethane foam had a porosity (ratio of the volume of the communication holes to the total volume) of 97%, and the size of the communication holes was 1200 μm in terms of the equivalent circle diameter.
An aqueous solution in which polyvinyl alcohol manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name Gohsenol GH-23 and phosphoric acid monoester was dissolved in ion-exchanged water was prepared. Polyvinyl alcohol was 1% by mass with respect to the total amount of the aqueous solution, and phosphoric acid monoester was 10% by mass with respect to the total amount of the aqueous solution. Pure aluminum powder of 10 μm or less (trade name 25E, manufactured by Eca Granular Co., Ltd.) and the above aqueous solution were mixed at a mass ratio of 5: 3 to prepare a slurry. It was 500 mPa * s when the viscosity of the slurry was measured with the E-type viscosity meter 50rpm.

  After the polyurethane foam was compressed to 2 mm by pressing, 100 g of slurry was press-fitted from a nozzle provided in the center of the upper plate of the press. After press-fitting, the press load was released to restore the polyurethane foam. Then, it dried at 80 degreeC for 120 minutes, and produced the aluminum slurry adhesion body.

(Comparative Example 1)
The same polyurethane foam and slurry as those in Example 1 were used.
The polyurethane foam was immersed in the slurry and included 400 g of the slurry. Next, the resin foam to which the slurry was attached was passed through a roll having a gap of 2 mm, and 300 g of the slurry was removed. Then, it dried at 80 degreeC for 120 minutes, and produced the aluminum slurry adhesion body.

(Comparative Example 2)
The same polyurethane foam and slurry as those in Example 1 were used.
The polyurethane foam was immersed in the slurry and included 400 g of the slurry. Next, the resin foam to which the slurry adhered was compressed to 2 mm by a press to remove 300 g of the slurry. Then, it dried at 80 degreeC for 120 minutes, and produced the aluminum slurry adhesion body.

(Evaluation)
About the obtained aluminum slurry adhesion body, distribution of the adhesion amount of the slurry of a slurry adhesion body side surface was observed visually. The results are shown in Table 1.

From Table 1, Example 1 was able to use only the amount of slurry to be adhered to the resin foam, and there was no adhesion amount distribution on the side surface of the resin foam.
However, Comparative Example 1 and Comparative Example 2 required several times as much slurry as the amount of the resin foam to be adhered, and had an adhesion amount distribution on the side surface of the resin foam.
When the aluminum slurry adhering body obtained in Example 1 was sintered at 670 ° C. for 180 minutes, a sintered body having a porosity of 97% and a communicating hole with an equivalent circle diameter of 1000 μm was obtained.

  Since the manufacturing method of the aluminum-based slurry adhering body according to one embodiment can reduce the amount of the slurry used when producing the slurry adhering body, and the slurry can be uniformly adhered to the resin foam. It is suitable for a production line of an adherent and an aluminum-based porous body using the same, particularly a mass production line.

1a, 1b Compression jig 2 Resin foam 3 Nozzle 10 Press device

Claims (4)

  An aluminum-based resin containing aluminum powder and / or aluminum alloy powder in a state where the resin foam is compressed into a resin foam having a skeleton that is three-dimensionally connected, and pores that are three-dimensionally communicated with the skeleton. The manufacturing method of the aluminum type slurry adhering body which press-fits a slurry and makes the said aluminum type slurry adhere to the said resin foam.   The porosity of the said resin foam is a manufacturing method of the aluminum-type slurry adhesion body of Claim 1 which is 90%-99%.   The average particle diameter of the said aluminum powder and / or the said aluminum alloy powder is a manufacturing method of the aluminum-type slurry adhesion body of Claim 1 or 2 which is 1 micrometer-50 micrometers. An aluminum-based slurry adherent is produced according to the method for producing an aluminum-based slurry adherent according to any one of claims 1 to 3, and the aluminum-based slurry adherent is heated to remove the resin foam. A method for producing a porous body.

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