JP6439550B2 - Porous aluminum sintered body, porous aluminum composite member, method for producing porous aluminum sintered body, method for producing porous aluminum composite member - Google Patents

Description

  The present invention relates to a porous aluminum sintered body obtained by sintering a plurality of aluminum fibers, a porous aluminum composite member, a method for producing a porous aluminum sintered body, and a method for producing a porous aluminum composite member.

  Conventionally, porous aluminum has been produced by sintering aluminum powder or adding a foaming aid to molten aluminum. Among these, porous aluminum sintered bodies have light weight, high specific surface area, and high open porosity, and are used for filters, electrode assemblies, silencers, heat exchanger members, and the like.

In the case of an aluminum porous current collector used as a positive electrode of a lithium ion battery, the higher the open porosity, the higher the volume filling density of the active material and the higher the capacity of the battery.
Moreover, when using a porous body as a cooling passage of the heat exchanger, the higher the open porosity, the larger the specific surface area, that is, the larger the heat exchange area, so that the heat exchange performance is improved. Furthermore, since the pressure loss (flow path resistance) of the heat medium (fluid) flowing through the inside decreases as the open porosity increases, when a porous body is used as the cooling passage of the heat exchanger, it is about 70 to 90%. It is preferable to use an aluminum porous body having a high open porosity.

However, when a porous aluminum sintered body is formed of aluminum powder, there is a problem that it is difficult to achieve both high strength and high porosity.
Since the aluminum powder is covered with a stable Al ₂ O ₃ oxide film, a porous molded body made of loosely packed aluminum powder (that is, low bulk density) as a raw material has a melting point of a general metal. Solid-phase sintering starting from a temperature of about 1/2 hardly progresses. On the other hand, near the melting point, the oxide film is destroyed by the volume expansion that occurs in the transition process from the solid phase to the liquid phase, and at the same time, the liquid phase sintering accompanying the spread of the melt between the powder particles and to the grain boundary, Since the rapid progress of the sintering shrinkage and the accompanying increase in density, it is difficult to advance the sintering while maintaining a high porosity. For these reasons, when forming a porous aluminum sintered body using aluminum powder as a raw material, it has been difficult to achieve both high strength and high porosity.

  In order to solve the above problem, Patent Document 1 discloses that a porous sintered body is manufactured by filling a bulk density of aluminum fibers to a true density ratio of 30% or more and then heating in a pressurized state to perform diffusion bonding. A method is disclosed.

  In Patent Document 2, as a method for producing a porous sintered body having a high porosity, metal fibers and metal powder particles are sintered together to make the metal powder particles a node between metal fibers. A method is disclosed.

JP 2011-007365 A Special table 2014-51083 gazette

  However, in the manufacturing method described in Patent Document 1, it is possible to sinter at 650 ° C. or lower, which is significantly lower than the melting point of pure aluminum, by firmly bringing aluminum fibers into contact with each other by pressing during sintering. However, since there is sintering shrinkage, a high porosity of 70% or more, which is the porosity at the initial filling, cannot be obtained in principle.

  In addition, the manufacturing method described in Patent Document 2 can be applied to nickel and stainless steel as in the embodiment of Patent Document 2, but aluminum has a strong oxide film formed on the surface as described above. There has been a problem that the sintered aluminum is impeded and a porous aluminum sintered body having sufficient strength cannot be obtained.

  The present invention has been made in view of the above circumstances, and has a porous aluminum sintered body having a high porosity and sufficient strength, a porous aluminum composite member, a method for producing a porous aluminum sintered body, It aims at providing the manufacturing method of a porous aluminum composite member.

The porous aluminum sintered body of the present invention is a porous aluminum sintered body obtained by sintering a plurality of aluminum fibers, and the aluminum fibers are made of aluminum or an aluminum alloy and have a diameter R of 0.02 mm or more and 1 The ratio L / R of the length L to the diameter R is in the range of 4 to 2500, and Fe is 0.01 mass in the porous aluminum sintered body. In addition to the aluminum fiber, Mg is included in an amount of 0.05% to 15.00% by mass, and the balance is an inevitable impurity, and apparent pores are included. The rate P is 50% or more and 95% or less, and the relative tensile strength Sr calculated in the following (1) is 2.0 N / mm ² or more.
Relative tensile strength Sr = S × 100 / (100−P) (1)
In the formula (1), S represents the maximum tensile strength (N / mm ² ), and P represents the apparent porosity (%).

According to the porous aluminum sintered body of the present invention configured as described above, the diameter R is in the range of 0.02 mm to 1.0 mm, and the ratio L / R of the length L to the diameter R is 4. Since the aluminum fibers in the range of 2500 or less are sintered together, a sufficient gap is secured between the aluminum fibers, and the apparent porosity is as high as 50% to 90%. A porous aluminum sintered body having a relative tensile strength of 2.0 N / mm ² or more can be obtained.

In addition, since the porous aluminum sintered body contains 0.1 mass% or more and 15.00 mass% or less of Mg that acts as a reducing agent for the Al ₂ O ₃ oxide film, the oxide film can be easily formed. It is easy to break, and the sintering bond can be promoted. As a result, since sintering at a significantly lower temperature is possible than the melting point of the aluminum fiber, it is possible to obtain a porous aluminum sintered body with high porosity because sintering shrinkage due to liquid phase sintering is suppressed. it can.
Furthermore, since Fe is contained in the porous aluminum sintered body in an amount of 0.01% by mass or more and 3.00% by mass or less, the sinterability is improved and the strength of the entire porous aluminum sintered body is increased. It becomes possible to raise.

  In addition, even if the individual fibers of the plurality of aluminum fibers have the same length, the porosity and the shape of the pores to be formed are those that are linear and those that are provided with shapes such as bending and twisting. Therefore, it is possible to control the porosity and the pore structure of the porous aluminum sintered body by varying various fiber shape factors including the length.

The porous aluminum composite member of the present invention is characterized in that a member main body and the above-described porous aluminum sintered body are joined.
According to the porous aluminum composite member having this configuration, the porous aluminum sintered body having a high porosity and excellent strength is firmly bonded to the member main body. The characteristics of the porous aluminum sintered body, which is excellent in various characteristics, are also exhibited as a porous aluminum composite member.

Method for producing a porous sintered aluminum of the present invention, the aluminum fibers is made A aluminum or aluminum alloy, the diameter R is in the range of less 1.0mm or 0.02 mm, the length L and the diameter R L / R is in the range of 4 or more and 2500 or less, and either or both of Mg powder and Mg alloy powder are fixed to the outer surface of the plurality of aluminum fibers, and the aluminum raw material for sintering A sintering aluminum raw material forming step for forming the sintering aluminum raw material laminating step for laminating the sintering aluminum raw material, and a sintering step for heating and sintering the laminated aluminum raw material for sintering, The content of Fe in the aluminum raw material for sintering is 0.01% by mass or more and 3.00% by mass or less, and the Mg powder and the Mg alloy powder The addition amount of the displacement or the other or both, and less 15.00 wt% 0.05 wt% or more in terms of Mg, in the sintering an aluminum material laminating process, true density D _T of the aluminum fiber bulk density D _P In the sintering step, the sintering aluminum material is placed in a temperature range of 590 ° C. to 655 ° C. in an inert gas atmosphere. It is characterized by sintering.
However, when the Mg component is already contained as an alloy component in the aluminum fiber, the addition amount of either or both of the Mg powder and the Mg alloy powder to be added in addition to the aluminum fiber is converted to Mg. The Mg component in the entire aluminum raw material for sintering is 0.05% by mass or more and 15.00% by mass or less.

In the method for producing a porous aluminum sintered body having this structure, either one or both of Mg powder and Mg alloy powder are added to pure aluminum fiber or aluminum alloy fiber and fixed to the outer surface of the fiber, and the aluminum raw material for sintering The porous aluminum sintered body is manufactured by sintering the raw material which made Mg content 0.05 to 15.00 mass% in conversion of Mg in the whole.
The above Mg powder and / or Mg alloy powder is heated in a state of being fixed to the surface of pure aluminum fiber or aluminum alloy fiber, thereby acting as a reducing agent for the oxide film of Al ₂ O ₃ and destroying the oxide film. Has the effect of facilitating the sinter bonding and promotes the sintering bond. In addition, Mg powder or / and Mg alloy powder fixed to the fiber surface locally reacts with the pure aluminum fiber or aluminum alloy fiber of the matrix, thereby causing a local matrix melting point lowering effect in the vicinity of the fixed part. Compared to the case where no additive is added, the liquid phase is locally generated at a lower temperature than the melting point of pure aluminum fiber or aluminum alloy fiber, thereby suppressing shrinkage due to sintering, that is, while maintaining the shape at the time of filling. It can promote ligation. As a result, a porous aluminum sintered body having a high porosity can be produced.

Moreover, 0.01 mass% or more and 3.00 mass% or less Fe are contained in the aluminum raw material for sintering. In the present invention, the Fe may be an Fe component contained in the aluminum fiber, or may be powdered Fe added separately from the Fe contained in the aluminum fiber.
Although the melting point lowering effect of Fe alone is small, when local melting of the matrix by Mg occurs, Fe exists between the unmelted aluminum fiber and the melted part, so that the inside of the unmelted aluminum fiber is introduced. It has the effect of inhibiting the diffusion of Mg and slowing the diffusion rate of Mg into the aluminum fiber. This is because the solubility of Mg in Fe is very small. Thereby, at the time of sintering, Mg is temporarily distributed at a high concentration on the surface of the aluminum fiber, and the melting point lowering effect of aluminum occurs only on the surface of the aluminum fiber. Can be promoted.

Here, in the method for producing a porous aluminum sintered body of the present invention, in the sintering aluminum raw material forming step, Fe powder is further fixed to the outer surfaces of the plurality of aluminum fibers, and the sintering aluminum raw material is formed. It is good also considering content of the said Fe powder in 0.01 to 3.00 mass%.
The aluminum fiber, which is a sintering raw material, contains Fe, depending on the type. However, the content varies depending on the aluminum fiber type. Therefore, in addition to Fe contained in the aluminum fiber, by containing 0.01 mass% or more and 3.00 mass% or less as the Fe content, it is possible to stably exhibit the above-described Fe sintering promotion. .

The method for producing a porous aluminum composite member of the present invention is a method for producing a porous aluminum composite member in which a member main body and an aluminum porous sintered body obtained by sintering a plurality of aluminum fibers are joined. Te, the aluminum fiber is made a aluminum or an aluminum alloy, is in the range diameter R less 1.0mm or 0.02 mm, the ratio L / R of the length L and the diameter R is 4 or more, 2500 or less And either one or both of Mg powder and Mg alloy powder are fixed to the outer surface of the plurality of aluminum fibers to form an aluminum raw material for sintering. The porous aluminum sintered body is formed by contacting the member main body and heating and sintering the sintering aluminum raw material and the member main body. In addition, in the method for joining the porous aluminum sintered body and the member main body, the Fe content in the sintering aluminum raw material is 0.01% by mass or more and 3.00% by mass or less, and the Mg The addition amount of either or both of the powder and the Mg alloy powder is 0.05 mass% or more and 15.00 mass% or less in terms of Mg, and the sintering aluminum raw material and the member main body are heated and sintered. In this case, sintering is performed at a temperature in the range of 590 ° C. to 655 ° C. in an inert gas atmosphere.
However, when the Mg component is already contained as an alloy component in the aluminum fiber, the addition amount of either or both of the Mg powder and the Mg alloy powder to be added in addition to the aluminum fiber is converted to Mg. The Mg component in the entire aluminum raw material for sintering is 0.05% by mass or more and 15.00% by mass or less.

  In the method for producing a porous aluminum sintered body having this configuration, the porous aluminum sintered body having the above-described high porosity and excellent strength is provided, and the porous aluminum excellent in various characteristics such as heat transfer characteristics. A composite member can be manufactured.

Here, in the method for producing a porous aluminum composite member of the present invention, when forming the sintering aluminum raw material, Fe powder is further fixed to the outer surfaces of the plurality of aluminum fibers, and the sintering aluminum is formed. It is good also considering content of the said Fe powder in a raw material as 0.01 mass% or more and 3.00 mass% or less.
The aluminum fiber, which is a sintering raw material, contains Fe, depending on the type. However, the content varies depending on the aluminum fiber type. Therefore, in addition to Fe contained in the aluminum fiber, by containing 0.01 mass% or more and 3.00 mass% or less as the Fe content, it is possible to stably exhibit the above-described Fe sintering promotion. . As a result, a porous aluminum sintered body having a high porosity and excellent strength is provided, and a porous aluminum composite member excellent in various characteristics such as heat transfer characteristics can be produced.

  According to the present invention, a porous aluminum sintered body having a high porosity and sufficient strength, a porous aluminum composite member, a method for producing a porous aluminum sintered body, and a method for producing a porous aluminum composite member are provided. be able to.

It is an expansion schematic diagram of the porous aluminum sintered compact which is this embodiment. It is a flowchart which shows an example of the manufacturing method of the porous aluminum sintered compact shown in FIG. It is explanatory drawing of the aluminum raw material for sintering which fixed either one or both of Mg powder particle and Mg alloy powder particle to the outer surface of the aluminum fiber. It is a schematic explanatory drawing of the continuous sintering apparatus which manufactures a sheet-like porous aluminum sintered compact. It is an external view explanatory drawing of the aluminum porous composite member which is this embodiment. It is a flowchart which shows an example of the manufacturing method of the porous aluminum composite member shown in FIG. It is explanatory drawing which shows the manufacturing process which manufactures a bulk-shaped porous aluminum sintered compact. It is an external view of the porous aluminum composite member which is other embodiment of this invention. It is an external view of the porous aluminum composite member which is other embodiment of this invention. It is an external view of the porous aluminum composite member which is other embodiment of this invention. It is an external view of the porous aluminum composite member which is other embodiment of this invention. It is an external view of the porous aluminum composite member which is other embodiment of this invention. It is an external view of the porous aluminum composite member which is other embodiment of this invention. It is an external view of the porous aluminum composite member which is other embodiment of this invention. It is a graph which shows the investigation result of the tensile strength and the apparent porosity of the porous aluminum sintered compact of a present Example. Test No. of this example. It is a figure which shows the SEM observation and composition analysis result of the junction part of the aluminum fibers in 1 (invention example) porous aluminum sintered compact.

  Below, porous aluminum sintered compact 10 and porous aluminum composite member 100 which are one embodiment of the present invention are explained with reference to the accompanying drawings.

<Porous aluminum sintered body>
FIG. 1 shows a porous aluminum sintered body 10 according to this embodiment. As shown in FIG. 1, a porous aluminum sintered body 10 according to the present embodiment is obtained by integrating a plurality of aluminum fibers 11 by sintering. In the porous aluminum sintered body 10, Fe is contained in an amount of 0.01% by mass or more and 3.00% by mass or less, and Mg is contained in an amount of 0.05% by mass or more and 15.00% by mass or less. In the present embodiment, the apparent porosity is set in the range of 50% to 90%.

In the present invention, the porosity (apparent porosity P) is the mass m (g) of the porous aluminum sintered body, the volume V (cm ³ ), and the true density d (g / cm ³ ) of the aluminum raw material for sintering. It can be measured and calculated by the following formula.
Apparent porosity P (%) = (1− (m ÷ (V × d))) × 100
The true density d (g / cm ³ ) can be measured by an underwater method using a precision balance.

  Here, the aluminum fiber 11 is made of pure aluminum or an aluminum alloy, the diameter R is in the range of 0.02 mm or more and 1.0 mm or less, and the ratio L / R of the length L to the diameter R is 4 or more. The range is 2500 or less.

(Diameter R)
When the diameter R of the aluminum fiber 11 is less than 0.02 mm, the bonding area between the aluminum fibers is small, and the sintered strength may be insufficient. On the other hand, when the diameter R of the aluminum fiber 11 exceeds 1.0 mm, the number of contacts with which the aluminum fibers contact each other is insufficient, and the sintering strength may be insufficient.
From the above, in the porous aluminum sintered body 10 according to the present embodiment, the diameter R of the aluminum fiber 11 is set in the range of 0.02 mm to 1.0 mm. In order to further improve the sintering strength, the diameter R of the aluminum fiber 11 is preferably 0.05 mm or more, and the diameter R of the aluminum fiber 11 is preferably 0.5 mm or less.

(Ratio of length L to diameter R: L / R)
If the ratio L / R of the length L and the diameter R of the aluminum fibers 11 is less than 4, in the manufacturing method described later porous sintered aluminum, the bulk density D _P when the stacked arrangement of the aluminum fibers It may be difficult to obtain 50% or less of the true density _DT , and it may be difficult to obtain the porous aluminum sintered body 10 having a high porosity. On the other hand, when the ratio L / R between the length L and the diameter R of the aluminum fibers 11 exceeds 2500, the aluminum fibers cannot be uniformly dispersed, and the porous aluminum sintered body has a uniform porosity. 10 may be difficult to obtain.
From the above, in the porous aluminum sintered body 10 according to the present embodiment, the ratio L / R between the length L and the diameter R of the aluminum fiber 11 is in the range of 4 or more and 2500 or less. In order to further improve the porosity, the ratio L / R between the length L and the diameter R of the aluminum fiber 11 is preferably 10 or more. In order to obtain a porous aluminum sintered body 10 having a more uniform porosity, the ratio L / R between the length L and the diameter R of the aluminum fibers 11 is preferably 500 or less.

(Mg: 0.05 mass% or more and 15.00 mass% or less)
The porous aluminum sintered body 10 contains 0.05 mass% or more and 15.00 mass% or less of Mg. When the Mg component is contained in the aluminum fiber, that is, when the aluminum alloy fiber containing the Mg component is used, 0.05% by mass of Mg is contained in the raw material separately from Mg contained in the aluminum alloy fiber. In the porous aluminum sintered body 10 finally obtained together with Mg contained in the aluminum alloy fiber, Mg is added in an amount of 0.05 mass% to 15.00 mass%. It is contained by mass% or less. On the other hand, when pure aluminum is used as the aluminum fiber, the amount of Mg added to the raw material is set to 0.05% by mass or more and 15.00% by mass or less.
Mg functions as a reducing agent for the oxide film of Al ₂ O ₃ , and has a function of promoting the sintering bond by making the oxide film brittle and easily breaking.
Further, Mg fixed to the surface of the aluminum fiber locally reacts with the aluminum fiber 11 (pure aluminum or aluminum alloy) of the matrix, thereby causing a local matrix melting point lowering effect in the vicinity of the fixed portion. As a result, sintering is promoted by forming a liquid phase at a lower temperature than when Mg is not added (that is, when Mg is not fixed).
However, if the Mg content is less than 0.05% by mass, the above-mentioned sintering improving effect is not sufficiently observed. If the Mg content exceeds 15.00% by mass, the liquidus temperature is remarkably lowered with respect to the melting point of aluminum. Therefore, when aluminum fibers 11 are laminated, partial melting easily occurs inside the laminated body. Thus, it is difficult to obtain the porous aluminum sintered body 10 having a uniform porosity, and it is difficult to join the member body when manufacturing the porous aluminum composite member. Therefore, in the porous aluminum sintered body 10 which is this embodiment, content of Mg shall be 0.05 mass% or more and 15.00 mass% or less. In order to improve the sinterability, the Mg content is preferably 0.30% by mass or more. Moreover, in order to obtain the porous aluminum sintered body 10 with a uniform porosity, it is preferable that content of Mg shall be 5.00 mass% or less.

(Fe: 0.01% by mass or more and 3.00% by mass or less)
The porous aluminum sintered body 10 contains Fe in an amount of 0.01% by mass to 3.00% by mass.
Fe has a small melting point lowering effect with Fe alone, but when the local matrix melting by Mg occurs, Fe is present between the unmelted Al fiber and the melted part, so that the unmelted aluminum fiber It has the effect of inhibiting the diffusion of Mg into the interior and slowing the diffusion rate. This is because the solid solubility of Mg in Fe is very small. For example, the solid solubility of Mg at 600 ° C. is 5 mass% Al: Fe is 0.1 mass% or less. Thereby, at the time of sintering, Mg is temporarily distributed at a high concentration on the surface of the aluminum fiber, the melting point lowering effect occurs only on the surface of the aluminum fiber, and the bonding between the aluminum fibers can be promoted. it can.
Since Mg gradually diffuses into Al as the sintering proceeds, Mg is in a solid solution in Al in the finally obtained porous aluminum sintered body. On the other hand, during high temperature sintering, Fe is also dissolved in about 1% by mass, but since Fe hardly dissolves in Al at room temperature, a part of Fe precipitates inside the aluminum fiber near the joint.
If the Fe content is less than 0.01% by mass, the above Mg diffusion suppressing effect is not sufficiently observed. On the other hand, if the Fe content exceeds 3.00% by mass, Fe is a high-melting intermetallic compound in the molten part. _{3 It} becomes easy to form Al, and sinterability deteriorates. Therefore, in the porous aluminum sintered body 10 which is this embodiment, content of Fe shall be 0.01 mass% or more and 3.00 mass% or less. In order to fully enjoy the Mg diffusion suppressing effect and obtain a porous aluminum sintered body 10 having a uniform porosity, the Fe content is preferably 0.05% by mass or more. Moreover, in order to suppress the formation of Fe ₃ Al and prevent deterioration of sinterability, the Fe content is preferably 1.00% by mass or less.

  In the present embodiment, the aluminum fiber 11 is given a shape such as twisting or bending. The shape of the aluminum fiber 11 is arbitrary, such as a straight line or a curved line, but when a predetermined shape imparting process is applied to at least a part of the aluminum fiber 11 by twisting or bending, the aluminum fiber The void shape between 11 can be formed three-dimensionally and isotropically, and as a result, the isotropy of various characteristics such as heat transfer characteristics of the aluminum porous sintered body is improved.

<Method for producing porous aluminum sintered body>
Next, a method for manufacturing the porous aluminum sintered body 10 according to the present embodiment will be described with reference to the flowchart of FIG.
Before describing the specific manufacturing process, first, the sintering aluminum raw material 20 that is a raw material of the porous aluminum sintered body 10 will be described.

  As shown in FIG. 3, the sintering aluminum raw material 20 includes one or both of Mg powder (Mg powder particles) 22 and Mg alloy powder (Mg alloy powder particles) 23 on the outer surface of the aluminum fiber 11. It is fixed. FIG. 3 shows the case where both the Mg powder 22 and the Mg alloy powder 23 are fixed.

Here, when an aluminum alloy is used as the aluminum fiber 11, Mg may be contained as an alloy component. Apart from this, Mg powder and / or Mg alloy powder is added to the sintering aluminum raw material 20 according to the present embodiment, and the added amount is 0.05 mass% or more and 13.00 mass% or less. . The composition of the entire aluminum raw material 20 for sintering combined with Mg contained in the aluminum alloy fiber is a composition containing 0.05% by mass or more and 15.00% by mass or less of Mg.
In addition, as above-mentioned, when using pure aluminum as an aluminum fiber, the addition amount of Mg to a raw material shall be 0.05 mass% or more and 15.00 mass% or less.
That is, it is important to add the Mg powder and / or the Mg alloy powder so that the Mg content in the entire sintering aluminum raw material 20 is 0.05% by mass or more and 15.00% by mass or less.
The type of the Mg alloy powder 23 is not particularly limited, and a Mg alloy powder 23 made of a general Mg alloy (for example, an Al—Mg alloy) can be used.

As the aluminum fiber 11, either pure aluminum or a general aluminum alloy can be suitably used.
When an aluminum alloy is used as the aluminum fiber 11, for example, an A3003 alloy (Al-0.6 mass% Si-0.7 mass% Fe-0.1 mass% Cu-1.5 mass% Mn- 0.1 mass% Zn alloy) and A5052 alloy (Al-0.25 mass% Si-0.40 mass% Fe-0.10 mass% Cu-0.10 mass% Mn-2.5 mass% Mg alloy) 0.2 mass% Cr-0.1 mass% Zn alloy).

  Further, the aluminum fiber 11 may be one in which pure aluminum powder (not shown) and / or aluminum alloy powder (not shown) adheres to the outer surface thereof, and has a desired composition depending on the purpose. You may adjust. When the aluminum alloy powder is adhered to the outer surface of the aluminum fiber 11, the type thereof is not particularly limited, and for example, powder made of JIS A3003 alloy can be used.

In addition, the aluminum raw material 20 for sintering contains 0.01% by mass or more and 3.00% by mass or less of Fe, and the Fe may be Fe contained in the aluminum fiber 11. Fe other than the Fe contained in may be added.
That is, when the sintering aluminum raw material 20 is prepared, 0.01 mass% or more as a whole of the sintering aluminum raw material 20 regardless of whether or not Fe is contained in addition to Fe in the aluminum fiber 11. The effect of the present invention is exhibited as long as it contains 00% by mass or less of Fe.
In addition, Fe exhibits the effect of suppressing the diffusion of Mg by being solid-solved in the aluminum fiber at the time of sintering or existing in the molten part of Mg. That is, even if Fe is previously contained in the aluminum fiber, the Fe is unevenly distributed on the fiber surface, and the same effect can be obtained as compared with the case where the Fe powder is fixed to the fiber outer surface. In addition, by adding Fe in the aluminum fiber in advance, a more uniform concentration distribution state can be obtained as compared with the case where Fe is added in the powder state. Therefore, Fe is added to the aluminum fiber in advance as an alloy element. It is better to keep it.

  As described above, the sintering aluminum raw material 20 according to the present embodiment contains 0.01 mass% or more and 3.00 mass% or less of Fe, and in addition to Mg in the aluminum fiber, another Mg is added in an amount of 0.001. The composition includes 05 mass% or more and 13.00 mass% or less (0.05 mass% or more and 15.00 mass% or less of the entire raw material), and the balance is an inevitable impurity. It may be contained as long as the effect is not impaired.

The Mg powder particles, the Mg alloy powder particles, and the Fe powder particles used as necessary are fixed to the aluminum fiber surface in the “sintering aluminum raw material forming step” described later, and then sintered in the “sintering step”. By doing so, it exerts a local melting point lowering effect and has a function of strengthening the sintering strength. In order to obtain a strong and homogeneous porous aluminum sintered body, in the “sintering aluminum raw material forming step”, Mg powder particles, Mg alloy powder particles, and Fe powder particles can be uniformly mixed with the aluminum fibers 11, And it is desirable to set it as the size which can be firmly fixed to the aluminum fiber surface.
Specifically, the average particle size of the Mg powder particles, the Mg alloy powder particles, and the Fe powder particles is 0.005 mm to 0.5 mm and 0.01 to 0.5 with respect to the aluminum fiber 11 diameter R. A ratio is desirable. If the average particle size of the Mg powder particles, the Mg alloy powder particles, and the Fe powder particles is less than 0.005 mm, the oxidation proceeds during sintering, and the necessary reduction effect and melting point reduction effect of Al ₂ O ₃ cannot be exhibited. Furthermore, Mg powder particles and Mg alloy powders have a risk of ignition due to dust explosion or contact with water, and there is a problem in safety at the time of production. On the other hand, when the average particle diameter of the Mg powder particles, the Mg alloy powder particles, and the Fe powder particles exceeds 0.5 mm, even if a predetermined amount is added, the number of added particles is small and a sufficient mixing effect cannot be obtained. Furthermore, there is a problem that the local melting (influence) range during sintering becomes large, and it becomes difficult to control the porosity.
If the ratio of the average particle diameter of the Mg powder particles, the Mg alloy powder particles, and the Fe powder particles to the diameter R of the aluminum fibers 11 is 0.01 or less, the powder and the aluminum fibers are easily separated during mixing. If the ratio is 0.5 or more, the particle diameter is too large with respect to the aluminum fiber diameter R, and a sufficient fixing effect cannot be obtained.

  Next, each process in the manufacturing method of the porous aluminum sintered body 10 which is this embodiment is demonstrated with reference to the flowchart of FIG.

"Sintering aluminum raw material formation process"
First, the sintering aluminum raw material formation process which manufactures the aluminum raw material 20 for sintering used as the raw material of the porous aluminum sintered compact 10 which is this embodiment is performed.
In addition, the aluminum raw material formation process for sintering which concerns on this embodiment is the mixing process S01 which mixes the aluminum fiber 11 and at least any one of Mg powder and Mg alloy powder with a binder, as shown in FIG. And a drying step S03 for drying the mixture obtained in the mixing step S01.

"Mixing process"
At normal temperature, the aluminum fiber 11 is mixed with one or both of the Mg powder and the Mg alloy powder (mixing step S01).
Here, when the composition of the porous aluminum sintered body 10 contains Fe different from the Fe in the aluminum fiber 11, the Fe powder is mixed together with the Mg powder and the Mg alloy powder in this mixing step. . The Fe powder is not particularly limited, and may be an alloy powder such as Fe-Mn.

  When mixing, the binder solution is sprayed. In addition, as a binder, what is combusted and decomposed | disassembled when heated to 500 degreeC in air | atmosphere is preferable, and it is preferable to specifically use an acrylic resin and a cellulose polymer. In addition, as the solvent for the binder, various solvents such as water-based, alcohol-based, and organic solvent-based solvents can be used.

  In this mixing step S01, for example, aluminum fibers 11, Mg powder, and Fe powder are used by using various mixing machines such as an automatic mortar, a bread type rolling granulator, a shaker mixer, a pot mill, a high speed mixer, and a V type mixer. And mix while flowing.

"Drying process"
Next, the mixture obtained in the mixing step S01 is dried (drying step S02).
Through the mixing step S01 and the drying step S02, as shown in FIG. 3, Mg powder 22 and Mg alloy powder 23 and, if necessary, Fe powder (not shown) are dispersed and fixed to the outer surface of the aluminum fiber 11. That is, the sintering aluminum raw material 20 according to the present embodiment is manufactured.

Next, the porous aluminum sintered body 10 is manufactured using the sintering aluminum raw material 20 obtained as described above.
Specifically, the sintering aluminum material lamination step S03 for laminating the sintering aluminum material 20, the debinding step S04 for removing the binder, and the laminated sintering aluminum material 20 are heated and sintered. Sintering process S05 is performed and the porous aluminum sintered compact 10 is manufactured.

Here, in this embodiment, using the continuous sintering apparatus 30 shown in FIG. 4, for example, a sheet-like porous aluminum sintered body 10 having a long width of 300 mm × thickness: 1 to 5 mm × length: 20 m. Manufacturing.
The continuous sintering apparatus 30 includes a raw material spreader 31 that uniformly spreads the aluminum raw material 20 for sintering, a carbon sheet 32 that holds the aluminum raw material 20 for sintering supplied from the raw material spreader 31, and the carbon sheet. Conveying roller 33 for driving 32, degreasing furnace 34 for removing the binder by heating the sintering aluminum material 20 conveyed together with the carbon sheet 32, and heating the sintering aluminum material 20 from which the binder has been removed. A sintering furnace 35 for sintering.

"Sintering aluminum raw material lamination process"
First, the aluminum material 20 for sintering is sprinkled on the carbon sheet 32 from the material spreader 31, and the aluminum material 20 for sintering is laminated and disposed (sintering aluminum material stacking step S03).
When the aluminum raw material 20 for sintering laminated | stacked on the carbon sheet 32 moves toward the advancing direction F, it spreads in the width direction of the carbon sheet 32, thickness is equalized, and it shape | molds in a sheet form. At this time, since no load is applied, a gap is formed between the aluminum fibers 11 and 11 in the sintering aluminum raw material 20.

Here, in the sintering raw aluminum laminating step S03, a bulk density D _P after filling is stacked a plurality of aluminum fibers 11 to be equal to or less than 50% of the true density D _T of the aluminum fibers 11. In the present embodiment, since the aluminum fibers 11 are subjected to shape imparting processing such as twisting and bending, three-dimensional and isotropic voids are secured between the copper aluminum fibers 11 during lamination. It will be.

"Debinding process"
Next, the sintering aluminum raw material 20 formed into a sheet shape on the carbon sheet 32 is charged into the degreasing furnace 34 together with the carbon sheet 32, and heated to a predetermined temperature to remove the binder (debinding). Binder process S04).
Here, in binder removal process S04, it hold | maintains at the temperature range of 350-500 degreeC in air | atmosphere for 0.5 to 5 minutes, and the binder in the aluminum raw material 20 for sintering is removed. In the present embodiment, as described above, since the binder is used only for the purpose of fixing the Mg powder 22, the Mg alloy powder 23 and, if necessary, the Fe powder to the outer surface of the aluminum fiber 11, the viscous composition is used. The content of the binder is extremely small compared to the product, and the binder can be sufficiently removed in a short time.

"Sintering process"
Next, the sintering aluminum raw material 20 from which the binder has been removed is charged into the firing furnace 35 together with the carbon sheet 32 and sintered by being heated to a predetermined temperature (sintering step S05).
In this sintering process S05, it hold | maintains by the temperature range of 590 degreeC-655 degreeC for 0.5 to 60 minutes in inert gas atmosphere. The optimum sintering temperature varies depending on the content of Mg in the aluminum raw material 20 for sintering. However, in order to realize high strength and uniform sintering, the sintering temperature is a liquid of Al-10 mass% Mg. The phase temperature is set to 590 ° C. or higher, and the generated liquid phase is set to 655 ° C. or lower in order to prevent rapid sintering shrinkage due to bonding between melts. The holding time is preferably 1 minute to 20 minutes.

  In this sintering step S05, a part of the aluminum fiber 11 in the sintering aluminum raw material 20 is melted, but since an oxide film is formed on the surface of the aluminum fiber 11, the molten aluminum Is retained by the oxide film, and the shape of the aluminum fiber 11 is maintained.

In the portion of the outer surface of the aluminum fiber 11 where the Mg powder particles 22 and the Mg alloy powder particles 23 are fixed, Mg acts as a reducing agent for the Al ₂ O ₃ oxide film, and the oxide film is destroyed and sintered. Bonding is promoted.
Further, Mg fixed on the surface of the aluminum fiber locally reacts with the aluminum fiber 11 to cause a local melting point lowering effect in the vicinity of the fixed portion. As a result, compared with the case where no Mg is added, the liquid phase is generated at a lower temperature than the melting point of the pure aluminum fiber or the aluminum alloy fiber, whereby the sintering is promoted and the strength is improved.
Further, Fe in the sintering aluminum raw material 20 exhibits a Mg diffusion suppressing effect by being in a solid solution in the aluminum fiber 11 at the time of sintering or in a local melting part generated by adding Mg.
In addition, since Mg gradually diffuses into the aluminum fiber 11 as the sintering proceeds, the Mg is dissolved in the aluminum fiber 11 in the finally obtained porous aluminum sintered body 10. It becomes. On the other hand, about 1% by mass of Fe also dissolves during high temperature sintering, but since Fe hardly dissolves in the aluminum fiber 11 at room temperature, a part of Fe precipitates inside the fiber near the joint.

According to the porous aluminum sintered body 10 of the present embodiment configured as described above, the diameter R is in the range of 0.02 mm to 1.0 mm, and the length L and the diameter R are Since the aluminum fiber 11 having the ratio L / R in the range of 4 or more and 2500 or less is sintered, a sufficient gap is secured between the aluminum fibers 11 and the porosity is 50. A porous aluminum sintered body having a high tensile strength of 2.0 N / mm ² or more can be obtained, which is as high as ˜90%.

Further, the porous aluminum sintered body 10 according to the present embodiment contains 0.05% by mass or more and 15.00% by mass or less of Mg that acts as a reducing agent for the oxide film of Al ₂ O ₃ . Therefore, the oxide film can be easily broken, and the sintering bond can be promoted. As a result, since sintering at a lower temperature is possible, a porous aluminum sintered body 10 having a high porosity can be obtained.
Furthermore, since the porous aluminum sintered body 10 contains 0.01 mass% or more and 3.00 mass% or less of Fe together with the above-mentioned Mg, the Mg diffusion suppression effect is exhibited and the sintering is performed. As a result, it is possible to increase the strength of the entire porous aluminum sintered body.

Moreover, in the manufacturing method of the porous aluminum sintered body 10 which is this embodiment, diameter R shall be in the range of 0.02 mm or more and 1.0 mm or less, and ratio L / R of length L and diameter R Mg fiber contained in the raw material by mixing aluminum fiber 11 having a value in the range of 4 or more and 2500 or less, and mixing either one or both of Mg powder and Mg alloy powder to adhere to the outer surface of the aluminum fiber. the raw materials but which was from 0.05 to 15.00 mass%, the bulk density _{D P} is provided with a stacking step S03 of stacked so that more than 50% of the true density _{D T} of the aluminum fibers 11, sintered Also in step S05, a gap between the aluminum fibers 11 can be secured, and shrinkage can be suppressed. Thereby, the porous aluminum sintered body 10 with high porosity and excellent dimensional accuracy can be manufactured.

<Porous aluminum composite member>
Next, the porous aluminum composite member 100 which is embodiment of this invention is demonstrated with reference to attached drawing.
FIG. 5 shows a porous aluminum composite member 100 according to this embodiment. The porous aluminum composite member 100 includes an aluminum plate 120 (member main body) made of pure aluminum or an aluminum alloy, and a porous aluminum sintered body 110 bonded to the surface of the aluminum plate 120.

Here, the porous aluminum sintered body 110 according to the present embodiment is obtained by sintering and integrating a plurality of aluminum fibers in the same manner as the porous aluminum sintered body 10 described above. Here, the aluminum fiber is made of pure aluminum or an aluminum alloy, the diameter R is in the range of 0.02 mm to 1.0 mm, and the ratio L / R of the length L to the diameter R is 4 or more and 2500. Within the following range. Moreover, in the porous aluminum sintered body 110, Fe is contained in an amount of 0.01% by mass to 3.00% by mass, and Mg is contained in an amount of 0.05% by mass to 15.00% by mass.
In the present embodiment, the aluminum fiber is provided with a shape such as twisting or bending.

Next, a method for manufacturing the porous aluminum composite member 100 according to the present embodiment will be described with reference to the flowchart of FIG.
First, the aluminum plate 120 which is a member main body is prepared (aluminum plate arrangement | positioning process S101).

Next, similarly to the sintering aluminum raw material forming step (mixing step S01, drying step S02) in the method for manufacturing the porous aluminum sintered body 10 described above, Mg powder and Mg are formed on the outer surfaces of the plurality of aluminum fibers. Either or both of the alloy powders are fixed to form an aluminum raw material for sintering.
This aluminum raw material for sintering is formed by fixing either one or both of Mg powder (Mg powder particles) and Mg alloy powder (Mg alloy powder particles) to the outer surface of the aluminum fiber.
In addition to Mg contained in the aluminum fiber, Mg powder is separately added to the sintering aluminum raw material according to the present embodiment, and the composition of the entire sintering aluminum raw material is pure aluminum fiber or aluminum alloy fiber. It is set as the composition which contains 0.05 mass% or more and 15.00 mass% or less including the part contained in it.
The aluminum raw material for sintering contains 0.01% by mass or more and 3.00% by mass or less of Fe. However, the Fe may be Fe contained in aluminum fibers, and is contained in aluminum fibers. Fe different from Fe to be added may be added.

Next, aluminum fibers are dispersed and arranged on the surface of the aluminum plate 120 (aluminum fiber lamination step S102). Here, in the aluminum fibers lamination step S101, bulk density D _P is stacked a plurality of aluminum fibers to be equal to or less than 50% of the true density D _T of the aluminum fibers.

Next, the aluminum plate 120 on which the aluminum raw material for sintering is laminated is heated in the air atmosphere to remove the binder (debinding process S103).
Thereafter, the porous aluminum sintered body 110 is formed on the aluminum plate 120 by charging in a firing furnace and holding in an inert gas atmosphere at a temperature range of 590 ° C. to 655 ° C. for 1 to 20 minutes. The porous aluminum sintered body 110 and the aluminum plate 120 are joined (sintering step S104).

In this sintering step S104, a part of the surface of the aluminum plate 120 is melted, but since the oxide film is formed on the surface of the aluminum plate 120, the molten aluminum is held by the oxide film, The shape of the aluminum plate 120 is maintained.
And in the portion where the Mg powder and Mg alloy powder are fixed on the surface of the aluminum plate 120, the Mg reacts locally with the aluminum plate 120, thereby causing a local melting point lowering effect in the vicinity of the fixed portion, The aluminum plate 120 and the porous aluminum sintered body 110 can be joined by producing a liquid phase at a lower temperature than the melting point of pure aluminum fiber or aluminum alloy fiber compared to when Mg is not added.

  According to the porous aluminum composite member 100 of the present embodiment configured as described above, the diameter R is within the range of 0.02 mm to 1.0 mm on the surface of the aluminum plate 120, and the length L / R ratio L / R is in the range of 4 or more and 2500 or less, Mg is 0.05 mass% or more and 15.00 mass% or less, Fe is 0.01 mass% or more and 3.00 mass% or less. A porous aluminum sintered body 110 having a high porosity, excellent strength and dimensional accuracy, which is formed by sintering aluminum fibers contained below, is joined, and is excellent in various characteristics such as heat transfer characteristics.

According to the method for manufacturing the porous aluminum composite member 100 according to the present embodiment, the diameter R is within the range of 0.02 mm or more and 1.0 mm or less on the surface of the aluminum plate 120, and the length L and the diameter R are The ratio L / R is in the range of 4 or more and 2500 or less, and Mg is contained in an amount of 0.05 mass% or more and 15.00 mass% or less, and Fe is contained in an amount of 0.01 mass% or more and 3.00 mass% or less. fibers, since the bulk density D _P is provided with an aluminum fiber lamination step S101 of laminating arranged to be less than 50% of the true density D _T of the aluminum fibers, also in the sintering step S104, between the aluminum fibers A gap can be secured and shrinkage can be suppressed. Thereby, the porous aluminum sintered body 110 with high porosity and excellent dimensional accuracy can be formed. Therefore, the porous aluminum composite member 100 excellent in various characteristics such as thermal conductivity can be manufactured.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
For example, although it demonstrated as what manufactures a porous aluminum sintered compact continuously using the continuous sintering apparatus shown in FIG. 4, it is not limited to this, Porous aluminum sintering by other manufacturing apparatuses The body may be manufactured.

Moreover, although this embodiment demonstrated as a sheet-like porous aluminum sintered compact, it is not limited to this, For example, the bulk-shaped porous aluminum sintered compact manufactured by the manufacturing process shown in FIG. It may be.
As shown in FIG. 7, from the raw material spreader 131 for spraying the sintering aluminum raw material 20, the sintering aluminum raw material 20 is sprayed into the carbon container 132 and filled, and if necessary, press molding is performed. (Raw material spraying process). This is charged into a degreasing furnace 134 and heated in an air atmosphere to remove the binder (debinding step). Then, it inserts in the baking furnace 135, and heat-maintains at 590 degreeC-655 degreeC by Ar atmosphere, Bulk-shaped porous aluminum sintered compact 10 'is obtained.
In this description, a carbon container 132 having good releasability is used, and a slight sintering shrinkage of about 1% occurs during sintering. The bonded body 10 'can be removed relatively easily.

  In the porous aluminum composite member 100 described above, the structure shown in FIG. 7 has been described as an example. However, the structure is not limited to this, and the porous aluminum composite having the structure shown in FIGS. 8 to 14 is used. It may be a member.

For example, as shown in FIG. 8, an aluminum porous composite member 200 having a structure in which a plurality of aluminum tubes 220 are inserted into a porous aluminum sintered body 210 as a member main body may be used.
Alternatively, as shown in FIG. 9, a porous aluminum composite member 300 having a structure in which a U-shaped aluminum tube 320 as a member main body is inserted into a porous aluminum sintered body 310 may be used. .

Furthermore, as shown in FIG. 10, a porous aluminum composite member 400 having a structure in which a porous aluminum sintered body 410 is joined to an inner peripheral surface of an aluminum tube 420 as a member main body may be used.
Moreover, as shown in FIG. 11, the aluminum porous composite member 500 of the structure which joined the porous aluminum sintered compact 510 to the outer peripheral surface of the aluminum tube 520 which is a member main body may be sufficient.

Furthermore, as shown in FIG. 12, a porous aluminum composite member 600 having a structure in which a porous aluminum sintered body 610 is joined to the inner peripheral surface and the outer peripheral surface of an aluminum tube 620 that is a member main body may be used.
Further, as shown in FIG. 13, a porous aluminum composite member 700 having a structure in which a porous aluminum sintered body 710 is bonded to both surfaces of an aluminum plate 720 as a member main body may be used.

Furthermore, as shown in FIG. 14, a porous aluminum composite member 810 having a structure in which a porous aluminum sintered body 810 is joined to at least a part of the outer peripheral surface of an aluminum multi-hole tube 820 that is a member main body may be used. Here, the aluminum multi-hole tube 820 has a flat shape and includes a plurality of through holes 821 serving as a flow path through which the heat medium flows.
For example, the porous aluminum composite member 800 shown in FIG. 14 is a carbon container having a rectangular parallelepiped shape, and the aluminum multi-hole tube 820 is penetrated from one side surface to the other side surface of the carbon container. It can be manufactured by disposing, spraying aluminum raw material for sintering into a carbon container, filling the bulk, and sintering.

Below, the result of the confirmation experiment performed in order to confirm the effect of this invention is demonstrated.
Aluminum raw materials for sintering shown in Table 1 were produced. This table shows the details of the aluminum fibers used, specifically the alloy type (JIS number), fiber diameter, length / diameter ratio (L / R), and Mg and Fe components contained in the raw material. As for the content (mass%), the amount contained in the aluminum fiber and the amount added separately from the aluminum fiber are shown separately.

  In this example, No. 1 in Table 1 was used. Weigh and add Mg powder, or Mg powder and, if necessary, Fe powder to a predetermined composition to aluminum fiber so as to have the composition shown in 1-29, and mix with a small amount of binder by V-type mixing mill Then, after each additive was fixed to the surface of the aluminum fiber, the carbon mold was bulk filled. In this example, Mg powder with a purity of 99% was used as the Mg powder, and reduced iron powder was used as the Fe powder.

Next, the filled aluminum raw material for sintering was held and sintered at the indicated sintering temperature for 30 minutes in an argon gas atmosphere to obtain a porous aluminum sintered body.
The obtained porous aluminum sintered body was measured for porosity and tensile strength by the following methods. The results are shown in Table 1, and a graph showing the relationship between the apparent porosity and the tensile strength is shown in FIG.
Moreover, the SEM observation and composition analysis result (X-ray element mapping image) of the joint part of the typical fiber observed by the porous aluminum sintered compact of test No. 1 (invention example) are shown in FIG.

(Apparent porosity)
The mass m (g), volume V (cm ³ ) of the obtained porous aluminum sintered body, and the true density d (g / cm ³ ) of the aluminum raw material for sintering were measured, and the apparent porosity was determined by the following formula: P was calculated.
Apparent porosity P (%) = (1− (m ÷ (V × d))) × 100
The true density d (g / cm ³ ) was measured by an underwater method using a precision balance.

(Tensile strength)
The obtained porous aluminum sintered body was processed into a test piece having a width of 10 mm, a length of 100 mm, and a thickness of 5 mm, and then subjected to a tensile test using an Instron type tensile tester to obtain a maximum tensile strength S (N / mm ² ) was measured. The maximum tensile strength S is a value obtained by dividing the measured maximum load (N) by the cross-sectional area (50 mm ² ) of the tensile test piece. Since the maximum tensile strength S obtained in this manner varies depending on the apparent porosity P, in this example, the relative maximum normalized by the apparent porosity P (%) according to the following formula in the present example. A tensile strength Sr (N / mm ² ) was defined, and a relative strength comparison evaluation was performed between materials having different apparent porosity.
Relative tensile strength Sr (N / mm ² ) = S × 100 / (100−P)

(Aluminum fiber diameter R and aluminum fiber length L)
As the aluminum fiber diameter R and the aluminum fiber length L, simple average values calculated by image analysis using a particle analyzer “Morphologi G3” manufactured by Malvern Co., Ltd. were used.

From the results shown in Table 1 and FIG. 15, a highly porous porous aluminum sintered body having a practically sufficient strength of 2.0 N / mm ² or more and a porosity of 50% or more is obtained according to the present invention. I can see that
Also, from the X-ray element mapping image of FIG. 16, Mg is present in a solid solution state inside the aluminum fiber, Fe is partly dissolved in Al, and part is in Al near the bond portion. Precipitates. From this, the simultaneous presence of Mg and Fe during the sintering causes a local and temporary melting point lowering effect of Mg on the fiber surface, so that after the sintering is promoted, the Mg is uniform in the matrix. It is considered that Fe is partly dissolved and partly precipitated in Al near the bonding portion.

In Test No. 23, the amount of Mg is small, and the effect of promoting the sintering cannot be sufficiently obtained. Therefore, in order to advance the sintering, the sintered porous aluminum sintered as a result of sintering at a high temperature close to the melting point. Only the body with an apparent porosity of 50% or less was obtained.
In Test No. 24, since the amount of Mg is too large, only a non-uniform sintered body can be obtained, and there are portions where the bonds are partially weak in the porous body, and only a porous aluminum sintered body having low strength is obtained. I couldn't.
In test No. 25, since the amount of Fe was too large, a sufficient sintering acceleration effect was not obtained, and only a porous aluminum sintered body having a remarkably low strength was obtained.
In Test No. 26, since the diameter of the aluminum fiber was too thin, the contact area between the aluminum fibers was small, so that a strong bonding point could not be formed, and only a porous aluminum sintered body with low strength was obtained.
In Test No. 27, since the diameter of the aluminum fiber was too large, a sufficient number of bonding points could not be formed at the time of sintering, and only a porous aluminum sintered body having a remarkably low strength was obtained.
In Test No. 28, since the L / R ratio was too small, a high bulk density could not be obtained at the time of filling, and as a result, a porous sintered body having a high porosity could not be obtained.
In test No. 29, since the L / R ratio was too large, the bonding inside the porous material became non-uniform, and a weakly bonded portion was generated partially. As a result, only a porous aluminum sintered body with low strength was obtained. .

  From the above, according to the present invention, it was confirmed that a high-quality porous aluminum sintered body having a high porosity and sufficient strength can be provided.

10, 10 'Porous aluminum sintered body 11 Aluminum fiber 20 Aluminum raw material for sintering 100 Porous aluminum composite member 120 Aluminum plate (member main body)

Claims (6)

A porous aluminum sintered body obtained by sintering a plurality of aluminum fibers,
The aluminum fibers consist A aluminum or an aluminum alloy, it is in the range diameter R less 1.0mm or 0.02 mm, and a range ratio L / R is 4 or more 2500 or less of the length L and the diameter R Has been
The porous aluminum sintered body contains Fe in an amount of 0.01% by mass to 3.00% by mass, Mg in an amount of 0.05% by mass to 15.00% by mass, and the balance being inevitable impurities. Having a composition
A porous aluminum sintered body having an apparent porosity P of 50% or more and 90% or less and a relative tensile strength Sr calculated by the following (1) of 2.0 N / mm ² or more.
Relative tensile strength Sr = S × 100 / (100−P) (1)
In the formula (1), S represents the maximum tensile strength (N / mm ² ), and P represents the apparent porosity (%).   A porous aluminum composite member obtained by joining a member main body and the porous aluminum sintered body according to claim 1. A method for producing a porous aluminum sintered body obtained by sintering a plurality of aluminum fibers,
The aluminum fibers is made A aluminum or an aluminum alloy, is in the range diameter R less 1.0mm or 0.02 mm, the length L and the range ratio L / R is 4 or more 2500 or less of the diameter R And
A sintering aluminum raw material forming step of fixing one or both of Mg powder and Mg alloy powder to the outer surface of the plurality of aluminum fibers to form an aluminum raw material for sintering;
A sintering aluminum material lamination step of laminating the sintering aluminum material;
A sintering step of heating and sintering the laminated aluminum raw material for sintering,
The content of Fe in the aluminum raw material for sintering is 0.01% by mass or more and 3.00% by mass or less,
The addition amount of one or both of the Mg powder and Mg alloy powder is 0.05 mass% or more and 15.00 mass% or less in terms of Mg,
Wherein the sintering in consolidating the aluminum material laminating process, the aluminum material for the plurality of sintered to a bulk density D _P equal to or less than 50% of the true density D _T of the aluminum fibers stacked,
In the sintering step, the sintering aluminum raw material is sintered at a temperature ranging from 590 ° C. to 655 ° C. in an inert gas atmosphere. In the sintering aluminum raw material forming step, further fixing Fe powder to the outer surface of the plurality of aluminum fibers,
The method for producing a porous aluminum sintered body according to claim 3, wherein the content of the Fe powder in the aluminum raw material for sintering is 0.01 mass% or more and 3.00 mass% or less. . A method for producing a porous aluminum composite member in which a member main body made of pure aluminum or an aluminum alloy and a porous aluminum sintered body formed by sintering a plurality of aluminum fibers are joined,
The aluminum fibers is made A aluminum or an aluminum alloy, is in the range diameter R less 1.0mm or 0.02 mm, the ratio L / R of the length L and the diameter R is 4 or more, 2500 or less in the range It is said that
Either one or both of Mg powder and Mg alloy powder is fixed to the outer surface of the plurality of aluminum fibers to form a sintering aluminum raw material, and the sintering aluminum raw material is brought into contact with the member main body, In the method of joining the porous aluminum sintered body and the member main body while forming the porous aluminum sintered body by heating and sintering the aluminum raw material for sintering and the member main body,
The content of Fe in the aluminum raw material for sintering is 0.01% by mass or more and 3.00% by mass or less,
The addition amount of one or both of the Mg powder and Mg alloy powder is 0.05 mass% or more and 15.00 mass% or less in terms of Mg,
A porous aluminum composite member characterized by sintering at a temperature in a range of 590 ° C to 655 ° C in an inert gas atmosphere when the sintering aluminum raw material and the member main body are heated and sintered. Manufacturing method. When forming the aluminum raw material for sintering, further fixing Fe powder to the outer surface of the plurality of aluminum fibers,
The method for producing a porous aluminum composite member according to claim 5, wherein the content of the Fe powder in the sintering aluminum raw material is 0.01 mass% or more and 3.00 mass% or less.