US20160221078A1 - Aluminum-based porous body and method for manufacturing same - Google Patents

Aluminum-based porous body and method for manufacturing same Download PDF

Info

Publication number
US20160221078A1
US20160221078A1 US15/025,497 US201415025497A US2016221078A1 US 20160221078 A1 US20160221078 A1 US 20160221078A1 US 201415025497 A US201415025497 A US 201415025497A US 2016221078 A1 US2016221078 A1 US 2016221078A1
Authority
US
United States
Prior art keywords
aluminum
strut
powder
porous body
based porous
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US15/025,497
Other languages
English (en)
Inventor
Hiroyuki Koshita
Zenzo Ishijima
Kei Ishii
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Showa Denko Materials Co ltd
Original Assignee
Hitachi Chemical Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Chemical Co Ltd filed Critical Hitachi Chemical Co Ltd
Publication of US20160221078A1 publication Critical patent/US20160221078A1/en
Assigned to HITACHI CHEMICAL COMPANY, LTD. reassignment HITACHI CHEMICAL COMPANY, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ISHII, KEI, ISHIJIMA, ZENZO, KOSHITA, Hiroyuki
Abandoned legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/11—Making porous workpieces or articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D25/00—Special casting characterised by the nature of the product
    • B22D25/005—Casting metal foams
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C7/00—Patterns; Manufacture thereof so far as not provided for in other classes
    • B22C7/02—Lost patterns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D21/00—Casting non-ferrous metals or metallic compounds so far as their metallurgical properties are of importance for the casting procedure; Selection of compositions therefor
    • B22D21/002—Castings of light metals
    • B22D21/007—Castings of light metals with low melting point, e.g. Al 659 degrees C, Mg 650 degrees C
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D25/00—Special casting characterised by the nature of the product
    • B22D25/02—Special casting characterised by the nature of the product by its peculiarity of shape; of works of art
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
    • B22D27/003—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting by using inert gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
    • B22D27/15—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting by using vacuum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/0003—
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/11—Making porous workpieces or articles
    • B22F3/1121—Making porous workpieces or articles by using decomposable, meltable or sublimatable fillers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/11—Making porous workpieces or articles
    • B22F3/1121—Making porous workpieces or articles by using decomposable, meltable or sublimatable fillers
    • B22F3/1137—Making porous workpieces or articles by using decomposable, meltable or sublimatable fillers by coating porous removable preforms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2301/00—Metallic composition of the powder or its coating
    • B22F2301/05—Light metals
    • B22F2301/052—Aluminium

Definitions

  • the present invention relates to a porous body having a strut, which is connected three-dimensionally, and having a three-dimensional network structure, which includes communicating holes that are formed by the strut so as to three-dimensionally communicate with each other.
  • the present invention relates to an aluminum-based porous body, which has a strut made of aluminum or aluminum alloy, and relates to a production method therefor.
  • Porous bodies having a strut, which is connected three-dimensionally, and having a three-dimensional network structure, which includes communicating holes that are three-dimensionally formed by the strut may be used as a filter (Japanese Unexamined Patent Applications Laid-Open Nos. 05-339605 (Patent document 1) and 08-020831 (Patent document 2)), a catalyst carrier (Patent document 2), etc.
  • the filter allows a fluid such as a gas or a liquid to pass through the communicating holes and to filter the fluid.
  • the catalyst carrier changes the fluid using a catalyst carried on the surface of the strut.
  • the porous bodies having such a three-dimensional network structure may be produced by the following method.
  • one method Japanese Unexamined Patent Application Laid-Open No. 57-174484 (Patent document 3)
  • the resin is decomposed by heating so as to be removed.
  • Patent documents 1 and 2 Japanese Examined Patent Application Publication No. 61-053417 (Patent document 4)
  • the resin is decomposed by heating so as to be removed, while the micro metal bodies are sintered.
  • Patent document 5 Japanese Unexamined Patent Application Laid-Open No. 06-235033 (Patent document 5)
  • the resin is decomposed by heating so as to be removed, while the powder is sintered.
  • a heat exchanger is a device that is used for heating or cooling by efficiently transferring heat from a higher temperature object to a lower temperature object.
  • a fluid such as a gas or a liquid is used as a medium for heat exchange, and the heat exchanger heats or cools by providing heat to (heat) or removing heat from (cool) the fluid.
  • the contact area with the fluid is increased by providing fins or the like, which are made of a metal material having a high thermal conductivity, whereby the heat exchange efficiency is increased.
  • porous bodies having a three-dimensional network structure which is made of a metal material with a high thermal conductivity may be used instead of the fins or the like, so that a fluid passes through communicating holes thereof.
  • the contact area between the metal material with a high thermal conductivity and the fluid may be further increased, whereby the heat exchange efficiency may be greatly improved.
  • Patent document 4 a mixture of an organic polymer binder and an aluminum powder is coated on a foamed resin, which has communicating holes, by immersing, spraying, or the like. Then, the resin is decomposed by heating at 520° C. for 2 hours in a hydrogen flow so as to be removed, while the micro metal bodies are sintered.
  • the aluminum powder particles have a strong oxide film (alumina: Al 2 O 3 ) on their surfaces, only a small portion of the aluminum powder particles are bonded to each other even by sintering, and only porous bodies, which are brittle and have very low strength, may be produced.
  • an object of the present invention is to provide an aluminum-based porous body having a three-dimensional network structure with sufficient strength and to provide a production method therefor.
  • this three-dimensional network structure aluminum powder particles or aluminum alloy powder particles, which initially have a strong oxide film on their surfaces, are used, and they are strongly bonded to each other.
  • the present invention provides an aluminum-based porous body having a strut, which is connected three-dimensionally, and having a three-dimensional network structure, which includes communicating holes that are formed by the strut so as to three-dimensionally communicate with each other.
  • the strut is made of aluminum or aluminum alloy having a density ratio of not less than 90% and contains an aluminum oxide that is dispersed in an inner part thereof.
  • the “aluminum” of the present invention is defined as aluminum, which consists of not less than 95 mass % of Al and the balance of impurities such as C and N and does not contain other metal elements.
  • the strut since the density ratio of the strut is not less than 90%, the strut has high strength. Moreover, since the aluminum oxide (alumina: Al 2 O 3 ) is dispersed in the strut, the aluminum matrix is strengthened, whereby the strut has further high strength.
  • the aluminum oxide alumina: Al 2 O 3
  • pores in the inner part of the strut preferably have a size of not greater than 10 ⁇ m from the viewpoint of the strength of the strut.
  • the aluminum oxide alumina: Al 2 O 3
  • the aluminum oxide preferably has a size (outermost diameter) of not greater than 10 ⁇ m.
  • the aluminum oxide is desirably contained in the strut at an area ratio of 5 to 20% in cross section. If the area ratio of the aluminum oxide is less than 5%, the effect for strengthening the matrix is not sufficiently obtained.
  • the area ratio of the aluminum oxide is greater than 20%, the strut is difficult to produce.
  • the area ratio of the oxide in the cross section of the strut can be measured by using image analyzing software (for example, “WinROOF” produced by Mitani Corporation) such that a cross sectional image of the strut is automatically binarized or the image is converted into a gray scale image, and an appropriate threshold value is set.
  • the aluminum-based porous body of the present invention may have a strut that is hollow, in one embodiment.
  • the present invention also provides an aluminum-based porous body having a strut, which is connected three-dimensionally, and having communicating holes, which are made to three-dimensionally communicate with each other by the strut.
  • This strut has a three-dimensional network structure that is made of aluminum or aluminum alloy.
  • This aluminum-based porous body shows a stress-strain diagram, in which a stress amount is increased with the increase in a strain amount when a load is applied, and the stress becomes approximately constant due to crushing of the communicating holes and is then increased.
  • the strut should be made so that the bonding between the aluminum powder particles does not break and the stress is increased in accordance with the increase in a strain amount, when a load is applied.
  • the strut is elastically deformed until a strain that is applied to the strut reaches a specific amount, and the strut is plastically deformed and the communicating holes, which three-dimensionally communicate with each other, start to be crushed, when the strain amount exceeds the specific amount.
  • the deformation of the aluminum-based porous body progresses in a condition in which the stress is not greatly increased (approximately constant) even when the strain amount is further increased.
  • the communicating holes, which three-dimensionally communicate with each other are crushed completely when the strain amount applied to the aluminum-based porous body is increased.
  • the elastic limit of the deformation of the strut is desirably not less than 0.5 MPa.
  • the strut is difficult to rupture and plastically deforms when a strain is applied at a specific amount or greater, because the aluminum powder particles are strongly bonded to each other.
  • the aluminum-based porous body preferably has a density ratio of the strut at not less than 90% from the viewpoint of the strength of the strut.
  • the pores in the inner part of the strut preferably have a size of not greater than 10 ⁇ m.
  • the amount of the crushed pieces, which are generated when a load is applied until the stress is increased after the stress is approximately constant in the stress-strain diagram, is preferably not more than 5 mass % of the aluminum-based porous body.
  • the aluminum-based porous body according to the present invention can be obtained by a production method for an aluminum-based porous body of the present invention.
  • This production method includes: using a resin three-dimensional network structure body, which has a resin strut that is connected three-dimensionally and which includes communicating holes that are formed by the resin strut so as to three-dimensionally communicate with each other, as a substrate, adhering at least one of aluminum powder and aluminum alloy powder on a surface of the resin strut of the substrate, and heating the adhered powder to not less than the melting point thereof in a nonoxidizing atmosphere so as to eliminate and remove the substrate and to melt the adhered powder.
  • the substrate having a resin strut, which is connected three-dimensionally, and having a resin three-dimensional network structure, which includes communicating holes that is formed by the resin strut so as to three-dimensionally communicate with each other is used.
  • at least one of the aluminum powder and the aluminum alloy powder is adhered on the surface of the resin strut of the substrate, and the resin substrate is then eliminated and removed by heating in the nonoxidizing atmosphere.
  • the adhered powder is heated to not less than the melting point thereof so as to be melted.
  • the aluminum powder and the aluminum alloy powder preferably have an average particle diameter of 1 to 50 ⁇ m.
  • the heating temperature is preferably set in a range of from the melting point to not higher than the melting point+100° C.
  • the surfaces of the powder particles are covered by an oxide film, and each of the powder particles contacts the other powder particle via the oxide film. Then, by heating the substrate, in which at least one of the aluminum powder and the aluminum alloy powder is adhered on the surface of the strut, to the melting point of the powder, the resin substrate is decomposed and eliminated in the heating step, and the melted powder particles break the oxide film, which is formed on their surfaces, and wet and cover their surfaces of powder particles.
  • the oxide film that is formed on the surfaces of the powder particles becomes a strut of the aluminum-based porous body in place of the resin strut, and the melted powder particles wet the outside of this strut, whereby adjacent powder particles are bonded with the melted powder particles. Therefore, the aluminum-based porous body that is obtained after the heating has strong metallurgical bonding, and a sufficient bonding strength is obtained.
  • the inventors of the present invention performed an experiment by using a copper powder in the same manner as in the production method of the present invention, the copper powder particles fell off when melted, and a porous body could not be formed. Accordingly, the capability of maintaining the shape even when the powder is melted is a specific effect of aluminum and aluminum alloy having the oxide film.
  • the strut of the aluminum-based porous body thus obtained has a density ratio of, for example, 90% or more, and is made of aluminum or aluminum alloy, which contains the oxide film, that is, alumina (Al 2 O 3 ), that is formed on the surfaces of the original powder particles, in the inner part thereof.
  • the alumina is hard, and it is dispersed in the matrix of the aluminum or the aluminum alloy and strengthens the matrix, whereby the aluminum or the aluminum alloy has high strength.
  • the density ratio of the strut cannot be measured by the Archimedes method, and therefore, the density ratio is calculated as a difference between an area (matrix portion except for hollow portions) in the cross section of the strut and an area ratio of pores that are dispersed in the matrix portion in the cross section of the strut by observing the cross section of the strut.
  • the area in the cross section of the strut and the area ratio of the pores of the strut may be measured by using image analyzing software (for example, “WinROOF” produced by Mitani Corporation) such that a cross sectional image of the strut is automatically binarized or the image is converted into a gray scale image, and an appropriate threshold value is set.
  • the final three-dimensional network structure of the aluminum-based porous body is obtained by melting the powder, which is at least one of the aluminum powder and the aluminum alloy powder and is adhered on, and is supported by, the surface of the strut of the substrate. Therefore, the three-dimensional network structure of the substrate affects the final three-dimensional network structure of the aluminum-based porous body. Accordingly, by changing the three-dimensional network structure of the substrate, an aluminum-based porous body having a desired three-dimensional network structure can be obtained.
  • the thickness of the strut is preferably set at 50 to 500 ⁇ m.
  • the strut of the aluminum-based porous body is formed by adhering at least one of the aluminum powder and the aluminum alloy powder on the surface of the resin strut of the substrate and by melting the powder.
  • the amount of the powder that is adhered on the surface of the resin strut of the substrate is great, an excessive amount of the melted adhered powder is generated, whereby the shape of the strut that is formed by the melted adhered powder is difficult to be maintained by the surface tension and tends to deteriorate.
  • the strut is made of aluminum or aluminum alloy with a preferable thickness of 50 to 500 ⁇ m after the melting.
  • the method for adhering at least one of the aluminum powder and the aluminum alloy powder on the surface of the resin strut of the substrate is exemplified below. That is, at least one of the aluminum powder and the aluminum alloy powder is dispersed in a dispersion medium and is then adjusted so that the viscosity will be 50 to 1000 Pa ⁇ s under a temperature condition of 25° C., whereby a dispersion liquid is obtained. Then, after a substrate is immersed in the dispersion liquid, the substrate is dried, whereby at least one of the aluminum powder and the aluminum alloy powder is adhered on the surface of the resin strut of the substrate.
  • the aluminum-based porous body of the present invention has high strength, and the aluminum-based porous body having such high strength is produced in a simple manner and at a low cost and is excellent in mass productivity, by the production method for the aluminum-based porous body of the present invention.
  • FIG. 1 is a schematic view showing a bonding condition between powder particles according to the production method for the aluminum-based porous body of the present invention.
  • FIG. 2 is a schematic view showing a bonding condition between powder particles according to a conventional production method for an aluminum-based porous body.
  • FIG. 3 is a view showing an aluminum-based porous body of an example of the present invention.
  • FIG. 4 is a view of a SEM image and a distribution of each element of a strut of an aluminum-based porous body of an example of the present invention, which was observed by an EPMA.
  • FIG. 5 is a view showing an aluminum-based porous body of a comparative example.
  • FIG. 6 is a stress-strain diagram of an aluminum-based porous body of each of an example of the present invention and a comparative example.
  • a three-dimensional network structure body which has a strut that is connected three-dimensionally and which includes holes formed by the strut so as to three-dimensionally communicate with each other, is used. Since the substrate is used for supporting at least one of the aluminum powder and the aluminum alloy powder that is adhered on the surface of the strut, and the substrate should be decomposed and eliminated by heating, the substrate is made of resin. Specifically, polyurethane foam may be generally used as the substrate, but a foam of silicone resin or polyester resin may also be used.
  • an aluminum powder is used as the powder to be adhered on the resin strut of the substrate in view of the balance of the thermal conductivity and the specific gravity.
  • an aluminum alloy powder in which aluminum is preliminarily alloyed with a component for strengthening aluminum, may be used instead of the aluminum powder.
  • the strut of the aluminum-based porous body is made of aluminum alloy, and the strength of the aluminum-based porous body is improved.
  • the thermal conductivity is decreased compared to the case of using only Al, the thermal conductivity is still sufficiently high because the base metal is Al.
  • the aluminum powder and the aluminum alloy powder a commonly used powder, that is, a powder having an oxide film (alumina: Al 2 O 3 ) of approximately 10 ⁇ on the surfaces of the powder particles, is used.
  • the powder of at least one of the aluminum powder and the aluminum alloy powder to be adhered on the resin strut of the substrate is preferably a fine powder because the fine powder can be adhered densely on the surface of the resin thin strut of the substrate. If the powder particles are large in size, the powder is difficult to adhere densely on the surface of the resin strut of the substrate. Moreover, since the mass of the powder is increased, the powder is difficult to adhere on the surface of the resin strut of the substrate and tends to peel off easily. In view of this, a powder having an average particle diameter of not greater than 50 ⁇ m is preferably used as the aluminum powder and the aluminum alloy powder.
  • a powder which has an average particle diameter of not greater than 50 ⁇ m and which does not include powder particles that have a particle diameter of greater than 100 ⁇ m is more preferable to use. It should be noted that excessively fine powder is difficult to handle because Al is an active metal. In view of this, a powder having an average particle diameter of not less than 1 ⁇ m is preferably used as the aluminum powder and the aluminum alloy powder.
  • each kind of the methods that are conventionally used may be applied. Typical methods are described below.
  • the wet method may be found in Patent documents 1, 2, 4, and the like, and is performed such that a dispersion liquid is prepared by dispersing at least one of an aluminum powder and an aluminum alloy powder in a dispersion medium, and a substrate is immersed in the dispersion liquid and is then dried.
  • a dispersion medium a liquid, which includes a volatile liquid such as alcohol, or water, as a solvent and includes a binder that is dissolved in the solvent, may be used.
  • a dispersion agent may be added in the dispersion medium so as to prevent the powder particles from precipitating.
  • a solution of an organic polymer such as phenol resin may be used as the dispersion medium.
  • the amount of the powder of at least one of the aluminum powder and the aluminum alloy powder to be adhered on the surface of the resin strut of the substrate can be controlled by the viscosity of the dispersion liquid. That is, if the viscosity of the dispersion liquid is high, the amount of the powder that is adhered on the surface of the resin strut of the substrate is great, and in contrast, if the viscosity of the dispersion liquid is low, the amount of the powder that is adhered on the surface of the resin strut of the substrate is small.
  • the viscosity of the dispersion liquid is excessively high, the amount of the powder that is adhered on the surface of the resin strut of the substrate is excessively increased, and the thickness from the surface of the resin strut exceeds 1000 urn, whereby the shape of the strut tends to be deteriorated in the heating step, which is described later.
  • the viscosity of the dispersion liquid is preferably set at not greater than 1000 Pa ⁇ s under a temperature condition of 25° C.
  • the viscosity of the dispersion liquid is excessively low, the amount of the powder that is adhered on the surface of the resin strut of the substrate is insufficient, whereby an aluminum-based porous body having a three-dimensional network structure with a thin strut is obtained after the heating step, and the strength of the aluminum-based porous body is decreased.
  • the viscosity of the dispersion liquid is preferably set at not lower than 50 Pa ⁇ s under a temperature condition of 25° C.
  • the viscosity can be measured by using a viscometer of TVB10 model produced by TOKI SANGYO CO., LTD., or the like, such that a torsion angle of two slit disks due to viscous torque is measured and is converted into the viscosity.
  • the dry method may be found in Patent document 5 and is performed as follows. That is, an adhesive solution such as of acrylic type or rubber type, or an adhesive resin solution such as of phenol resin, epoxy resin, or furan resin, is coated on the surface of the substrate so as to provide adhesiveness. Then, the substrate is vibrated in powder or is sprayed with the powder so that the powder adheres the surface of the strut.
  • an adhesive solution such as of acrylic type or rubber type, or an adhesive resin solution such as of phenol resin, epoxy resin, or furan resin
  • the substrate After at least one of the aluminum powder and the aluminum alloy powder is adhered on the surface of the strut, the substrate is heated to not less than the melting point of the adhered powder in a nonoxidizing atmosphere. The resin substrate is decomposed, and it is eliminated and removed, while the temperature is increased to the melting point.
  • the heating temperature exceeds the melting point of aluminum (melting point: 660.4° C.) or the aluminum alloy
  • the inner parts of the aluminum powder particles or the aluminum alloy powder particles are melted. That is, since the surfaces of each of the aluminum powder particles and the aluminum alloy powder particles are covered with an oxide film (alumina: Al 2 O 3 ), and the melting point of alumina is such a high temperature as 2072° C., the oxide film on the surfaces of each of the aluminum powder particles and the aluminum alloy powder particles is not melted, but the inner part of these powder particles is melted.
  • the aluminum or the aluminum alloy that is thus melted in the inner part of the powder particles breaks the oxide film of the surfaces of the powder particles and wets and covers the surfaces of the powder particles, and the melted aluminum or the melted aluminum alloy, which is generated from respective powder particles, is mixed and is bonded together, as shown in FIG. 1 , At this time, the oxide film that is formed on the surfaces of the powder particles becomes a strut of the aluminum-based porous body in place of the resin strut and maintains the shape of the resin strut.
  • the surface of this strut is relatively smooth due to the surface tension of the melted aluminum or the melted aluminum alloy, which is bonded to each other, and is also a continuous metal surface because neck portions are eliminated.
  • the strut of the aluminum-based porous body that is thus obtained is made of aluminum or the aluminum alloy, which contains the oxide film, that is, alumina (Al 2 O 3 ), that is formed on the surfaces of the original powder particles, in the inner part thereof.
  • the alumina is hard and is dispersed in the matrix of the aluminum or the aluminum alloy, thereby strengthening the matrix.
  • this strut includes cavities at the portions where the resin strut existed, and is hollow, and therefore, this strut may be effectively used in cases requiring reduction in weight.
  • the heating temperature is less than the melting point of aluminum or the aluminum alloy, as shown in FIG. 2 , the strong oxide film that is formed on the surfaces of the aluminum powder particles or the aluminum alloy powder particles act as a barrier. Therefore, the aluminum powder particles or the aluminum alloy powder particles are prevented from being diffusion-bonded to each other, whereby the sintering is difficult to proceed.
  • the heating step is desirably performed in a nonoxidizing atmosphere such as of nitrogen gas, inert gas, or the like. It is not necessary to use a reducing atmosphere such as of hydrogen gas, hydrogen mixed gas, or the like, in the heating step because the oxide film on the surfaces of the aluminum powder particles or the aluminum alloy powder particles should not be removed. Nevertheless, since the reducing atmosphere is a nonoxidizing atmosphere, the reducing atmosphere may be used. Alternatively, a reduced-pressure atmosphere (vacuum atmosphere), in which the pressure is not greater than 10 ⁇ 3 Pa, may be used.
  • the aluminum powder or the aluminum alloy powder, which is adhered on the substrate can be melted at a heating temperature that is higher than the melting point thereof.
  • the heating temperature is preferably set in a range of from the melting point to the melting point+100° C.
  • the strut of the aluminum-based porous body having the three-dimensional network structure is excessively thin, the strength of the aluminum-based porous body is decreased. On the other hand, if the strut of the aluminum-based porous body is excessively thick, the fluid is prevented from passing through the communicating holes, and the pressure loss is increased.
  • the strut of the aluminum-based porous body is formed by adhering at least one of the aluminum powder and the aluminum alloy powder on the surface of the resin strut of the substrate and by melting the powder. In this case, when the amount of the powder that is adhered on the surface of the resin strut of the substrate is increased, the amount of the melted adhered powder is increased.
  • the thickness of the strut of the aluminum-based porous body is preferably set at 50 to 500 ⁇ m. Moreover, it is preferable to adhere at least one of the aluminum powder and the aluminum alloy powder on the surface of the resin strut so that the thickness will be 100 to 1000 ⁇ m from the surface of the resin strut.
  • the strut is made of aluminum or the aluminum alloy with a preferable thickness of 50 to 500 ⁇ m after the melting.
  • the three-dimensional network structure of the aluminum-based porous body that is produced by the above production method maintains the three-dimensional network structure of the resin substrate as it is. Therefore, by changing the three-dimensional network structure of the resin substrate, the three-dimensional network structure of the aluminum-based porous body can be changed, and the hole ratio of the entirety of the aluminum-based porous body and the size of the holes can be adjusted as desired.
  • the aluminum-based porous body can be made so as to have a hole ratio of 80 to 95%, preferably 85 to 95%, and so as to include the holes having sizes of 30 to 4000 ⁇ m, and a porous body of 6 to 80 ppi (cells/25.4 mm) is easily produced.
  • the following idea may be conceived. That is, a component such as Cu, Mg, or the like, which generates a liquid phase of a eutectic composition in combination with Al, may be used as a raw powder in the form of a single powder or an aluminum alloy powder. This raw powder may be added in the aluminum powder, whereby an aluminum based mixed powder may be prepared. Then, the aluminum based mixed powder may be adhered on the surface of the resin substrate having the three-dimensional network structure and be sintered at a temperature at which the liquid phase of the eutectic composition is generated.
  • the distributions of the component elements in the aluminum-based porous body tend to not be uniform, and the aluminum oxide is not dispersed in the inner part of the strut, whereby a desired strength is difficult to obtain.
  • the distributions of the component elements in the aluminum-based porous body is made uniform.
  • the aluminum oxide that is generated due to the production method is dispersed in the inner part of the strut. Therefore, high strength can be obtained compared to the case of performing the idea of using the aluminum based mixed powder and sintering by generating a liquid phase of the eutectic composition.
  • polyurethane foam As a resin substrate having a three-dimensional network structure, polyurethane foam (Product name: Everlight SF, produced by Bridgestone Corporation) having a length of 10 mm, a width of 20 mm, and a thickness of 10 mm, was prepared.
  • the polyurethane foam had a hole ratio (ratio of the volume of communicating holes to the volume of the entirety) of 95% and had communicating holes with a circle equivalent diameter of 3000
  • polyvinyl alcohol Product name: GOHSENOL GH-23, produced by The Nippon Synthetic Chemical Industry Co., Ltd.
  • resin at 1 mass was prepared as a dispersion medium.
  • the dispersion medium and an aluminum powder having an average particle diameter of 6 ⁇ m were mixed in a mass ratio of 1:1, whereby an aluminum powder dispersed liquid (viscosity at 25° C.: 50 to 75 Pa ⁇ s, measured by a viscometer of TVB10 model produced by TOKI SANGYO CO., LTD.) was obtained.
  • an aluminum powder dispersed liquid viscosity at 25° C.: 50 to 75 Pa ⁇ s, measured by a viscometer of TVB10 model produced by TOKI SANGYO CO., LTD.
  • the hole ratio of each of these porous samples was measured by the Archimedes method.
  • the size of pores and the circle equivalent diameter of the holes (communicating holes) of the three-dimensional network structure were measured by observation using an optical microscope and by using image analyzing software (“WinROOF” produced by Mitani Corporation), and an average value of each of the size of the pores and the circle equivalent diameter of the holes was calculated.
  • the porous samples were embedded in resin, and the porous samples were mirror polished and were etched with Keller's reagent (hydrochloric acid: 0.5 ml, nitric acid: 2.5 ml, hydrofluoric acid: 1.5 ml, distilled water: 95 ml). Then, the metallic structure of the strut portion was observed.
  • the image analyzing software (“WinROOF” produced by Mitani Corporation), the image was binarized, and an area ratio of the strut portion (matrix portion except for hollow portions) and an area ratio in the cross section of the pores, which were dispersed in the strut portion (matrix portion except for hollow portions) were measured, whereby a density ratio of the strut portion was calculated.
  • each of the aluminum-based porous body samples of samples Nos. 01 to 07 was subjected to a compressive yield test, and a strain amount and a stress were measured while a compressive load was increased, whereby a stress-strain diagram was formed. Then, the stress when entering a plateau region, in which the stress was approximately constant, was calculated from the stress-strain diagram, and the result is also shown in Table 1.
  • the hole ratio was approximately the same as that of the urethane foam that was used as the substrate, and the size of the communicating holes was also approximately the same as that of the urethane foam of the substrate. According to this result, the hole ratio and the size of the communicating holes of the urethane foam of the substrate are maintained in the porous samples as they are.
  • the density ratio of the strut portion was not less than 90% and was high.
  • the pores of the strut portion were as small as 2 to 10 ⁇ m.
  • oxides were dispersed in the inner part of the strut portion, and the oxide had a size of 10 ⁇ m and had an area ratio of 8% in cross section.
  • the samples Nos. 01 to 03 which are comparative examples, only a small portion of the aluminum powder particles were bonded, and the oxides existed only on the surfaces of the aluminum powder particles and were not dispersed in the inner part of the matrix.
  • FIG. 3 shows a view in which the condition of pores in the porous sample of sample No. 04 of the example of the present invention was observed.
  • the melted aluminum bonded the adjacent powder particles, and the surface of the strut was relatively smooth due to the surface tension of the melted aluminum and had a metal continuous surface because neck portions were eliminated.
  • FIG. 4 shows a view of a SEM (Scanning Electron Microscope) photograph of a cross section of the strut portion of the aluminum-based porous body of the example of the present invention, which was observed by an EPMA (Electron Probe MicroAnalyser).
  • FIG. 4 also shows a mapped image showing distribution of each of the components of Al and O (Oxygen).
  • Al 2 O 3 alumina
  • FIG. 5 shows a view in which the condition of pores in the porous sample of sample No. 03, which is a comparative example.
  • sample No. 03 which is a comparative example.
  • FIG. 5 shows a view in which the condition of pores in the porous sample of sample No. 03, which is a comparative example.
  • the porous sample of the comparative example only a part of the aluminum powder particles were bonded by solid phase diffusion, and neck portions (bonded portions of the powder particles) did not grow. Therefore, the shapes of the original powder particles were observed.
  • the elastic limit was 0.5 MPa or higher until the stress reached the plateau region.
  • the elastic limit was increased to 1.7 MPa in accordance with the increase in the density ratio.
  • the result of the compressive yield test was described in detail with reference to FIG. 6 .
  • the aluminum-based porous body sample of sample No. 04 which is the example of the present invention, was elastically deformed at the initial stage of the deformation, and the stress was increased with the increase in the strain amount. Then, the stress becomes constant although the strain amount was increased. In this condition, the deformation proceeded while the communicating holes of the aluminum-based porous body sample were compressed and were closed.
  • the stress was increased in accordance with the increase in the strain amount while the load was increased, as in the case of an ordinary metallic sample.
  • Such deformation behavior is typical for the aluminum-based porous body sample.
  • the aluminum-based porous body sample of the present invention showed a stress-strain diagram, in which the stress amount is increased with the increase in the strain amount when the load is applied, and the stress becomes approximately constant due to crushing of the communicating holes and is then increased.
  • This aluminum-based porous body sample had higher strength than the conventional aluminum-based porous body sample.
  • the aluminum-based porous body of the present invention has high strength, and therefore, it is preferably used for various kinds of porous members.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Powder Metallurgy (AREA)
US15/025,497 2013-09-30 2014-09-26 Aluminum-based porous body and method for manufacturing same Abandoned US20160221078A1 (en)

Applications Claiming Priority (9)

Application Number Priority Date Filing Date Title
JP2013204881 2013-09-30
JP2013-204881 2013-09-30
JP2013204879 2013-09-30
JP2013-204886 2013-09-30
JP2013204886 2013-09-30
JP2013-204879 2013-09-30
JP2014-111249 2014-05-29
JP2014111249 2014-05-29
PCT/JP2014/076475 WO2015046623A1 (ja) 2013-09-30 2014-09-26 アルミニウム系多孔質体およびその製造方法

Publications (1)

Publication Number Publication Date
US20160221078A1 true US20160221078A1 (en) 2016-08-04

Family

ID=52743742

Family Applications (1)

Application Number Title Priority Date Filing Date
US15/025,497 Abandoned US20160221078A1 (en) 2013-09-30 2014-09-26 Aluminum-based porous body and method for manufacturing same

Country Status (6)

Country Link
US (1) US20160221078A1 (ja)
JP (1) JP6132026B2 (ja)
KR (2) KR20170139688A (ja)
CN (1) CN105579167A (ja)
DE (1) DE112014004497T5 (ja)
WO (1) WO2015046623A1 (ja)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106825541A (zh) * 2016-12-26 2017-06-13 有研粉末新材料（北京）有限公司 一种粘结粉末的制备方法
US10677590B2 (en) * 2017-05-18 2020-06-09 Grob-Werke Gmbh & Co. Kg Method and device for assessing the quality of coated surfaces

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016142420A (ja) * 2015-01-30 2016-08-08 日立化成株式会社 熱交換器用多孔質部材
CN107779639A (zh) * 2016-08-31 2018-03-09 国研高能（北京）稳态传热传质技术研究院有限公司 一种开孔海绵结构的铝质材料及其制备方法
KR102141058B1 (ko) 2018-04-23 2020-08-04 주식회사 포스코 리튬 흡착 성형체 및 그의 제조 방법

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5222118B2 (ja) * 1973-02-22 1977-06-15
JPS57174484A (en) 1981-04-20 1982-10-27 Sumitomo Electric Ind Ltd Production of metallic porous body of micropore sized foam structure
JPS6153417A (ja) 1984-08-18 1986-03-17 Yamaha Motor Co Ltd 車両のｖ型２サイクルエンジン
JPH05339605A (ja) 1992-06-09 1993-12-21 Japan Metals & Chem Co Ltd 多孔金属の製造方法
JPH0689376A (ja) 1992-09-07 1994-03-29 Osamu Masaki 改ざん不能な磁気カード
JP3407813B2 (ja) 1993-02-10 2003-05-19 日立化成工業株式会社 三次元網目構造体の製造方法
JPH0820831A (ja) 1994-07-07 1996-01-23 Sumitomo Electric Ind Ltd 金属多孔体の製造方法
JP3568052B2 (ja) * 1994-12-15 2004-09-22 住友電気工業株式会社 金属多孔体、その製造方法及びそれを用いた電池用極板
JP2003328054A (ja) * 2002-05-16 2003-11-19 Hitachi Powdered Metals Co Ltd アルミニウム系合金部材の製造方法
CN1244710C (zh) * 2002-09-02 2006-03-08 北京有色金属研究总院 一种复合金属多孔体及其制备方法
US7036550B2 (en) * 2002-09-27 2006-05-02 University Of Queensland Infiltrated aluminum preforms
JP2012007233A (ja) * 2010-04-22 2012-01-12 Sumitomo Electric Ind Ltd アルミニウム構造体の製造方法およびアルミニウム構造体

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106825541A (zh) * 2016-12-26 2017-06-13 有研粉末新材料（北京）有限公司 一种粘结粉末的制备方法
US10677590B2 (en) * 2017-05-18 2020-06-09 Grob-Werke Gmbh & Co. Kg Method and device for assessing the quality of coated surfaces

Also Published As

Publication number Publication date
DE112014004497T5 (de) 2016-07-21
JPWO2015046623A1 (ja) 2017-03-09
KR20170139688A (ko) 2017-12-19
KR20160067897A (ko) 2016-06-14
CN105579167A (zh) 2016-05-11
JP6132026B2 (ja) 2017-05-24
WO2015046623A1 (ja) 2015-04-02

Similar Documents

Publication Publication Date Title
US20160221078A1 (en) Aluminum-based porous body and method for manufacturing same
EP1735122B1 (en) A metal foam body having an open-porous structure as well as a method for the production thereof
JP6355920B2 (ja) アルミニウム電解コンデンサ用電極箔及びその製造方法
EP3769867B1 (en) Porous titanium-based sintered body, method for producing the same, and electrode
JP2016183390A (ja) 金属多孔質体
WO2013002532A2 (ko) 산소 원자 분산된 금속 기지 복합재 및 그 제조 방법
WO2023127361A1 (ja) チタン多孔質体及び、チタン多孔質体の製造方法
Feng et al. Microstructures and properties of the copper‐coated SiCp Reinforced Al–Si alloy composites
WO2019188480A1 (ja) 多孔質チタン系焼結体、その製造方法及び電極
US11597012B2 (en) Article and method
JP2017171991A (ja) アルミニウム多孔質体の製造方法
Masiha et al. Effect of nanocrystalline surface of substrate on microstructure and wetting of PEO coatings
US9579722B1 (en) Method of making an apparatus for transpiration cooling of substrates such as turbine airfoils
JP2001348288A (ja) 粒子分散シリコン材料およびその製造方法
JP2007177280A (ja) 金属多孔質体の製造方法
JP2019214775A (ja) アルミニウム系多孔質体及びその製造方法
JP2016141824A (ja) アルミニウム系多孔質体およびその製造方法
JP7182323B2 (ja) 硬質合金複合部材の製造方法及び真空吸着装置の製造方法
JP2008007811A (ja) 金属多孔質体の製造方法
JP2016142420A (ja) 熱交換器用多孔質部材
JP2016183386A (ja) アルミニウム系多孔質体
JP6897237B2 (ja) 接合用成形体及びその製造方法
JP2017150053A (ja) アルミニウム系多孔質体およびその製造方法
JP2022145220A (ja) 硬質合金複合部材及びその製造方法並びに真空吸着装置及びその製造方法
CN115121797A (zh) 一种多孔铝复合板的制备方法

Legal Events

Date Code Title Description
AS Assignment

Owner name: HITACHI CHEMICAL COMPANY, LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KOSHITA, HIROYUKI;ISHIJIMA, ZENZO;ISHII, KEI;REEL/FRAME:039344/0182

Effective date: 20160725

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION