JP2017197811A - Copper porous body, copper porous composite member, manufacturing method of copper porous body and manufacturing method of copper porous composite member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copper porous body having sufficient conductivity and thermal conductivity even when porosity is high and especially suitable as a conductive member and a thermal conductive member, a copper porous composite member where the copper porous body is conjugated to a member body, a manufacturing method of the copper porous body and a manufacturing method of the copper porous composite member.SOLUTION: There is provided a copper porous body having a skeleton part with a three-dimensional network, porosity in a range of 50% to 90% and porosity standardized conductivity defined by dividing conductivity of the porous body measured by a 4-terminal method by apparent density ratio of the copper porosity, σ, of 20%IACS or more.SELECTED DRAWING: None

Description

  The present invention relates to a copper porous body made of copper or a copper alloy, a copper porous composite member obtained by bonding the copper porous body to a member body, a method for producing a copper porous body, and a copper porous composite. The present invention relates to a method for manufacturing a member.

The above-mentioned copper porous body and copper porous composite member are used as, for example, electrodes and current collectors in various batteries, heat exchanger members, heat pipes, and the like.
For example, in Patent Document 1, as a method for producing a metal sintered body (copper porous sintered body) forming a three-dimensional network structure, a three-dimensional network structure (for example, urethane foam, made of a material that is burned down by heating) is disclosed. Polyethylene foam, synthetic resin foam with continuous cells, natural fiber cloth, man-made fiber cloth, etc.). And a method of using a sheet-like molded body in which a metal powder is formed on a material (for example, pulp or wool fiber) that can form a three-dimensional network structure.
Patent Document 2 discloses a method of obtaining a porous material by conducting current heating under pressure on copper fibers.

Japanese Patent Laid-Open No. 08-145592 Japanese Patent No. 3735712

By the way, in the above-mentioned copper porous body, in addition to having a high porosity and an open cell structure, when used as a conductive member such as an electrode and a current collector, excellent conductivity is required, and for a heat exchanger. When used as a heat transfer member such as a member or a heat pipe, excellent thermal conductivity is required.
In the copper porous bodies described in Patent Document 1 and Patent Document 2, conductivity and thermal conductivity are not considered, and in particular, when the porosity is high, bonding between copper powder or copper fibers is not possible. As a result, there is a possibility that the conductivity and thermal conductivity may be insufficient.

  The present invention has been made against the background as described above, and has sufficient conductivity and thermal conductivity even when the porosity is high, and is particularly suitable as a conductive member and a heat transfer member. An object of the present invention is to provide a copper porous body, a copper porous composite member in which the copper porous body is bonded to a member body, a method for producing a copper porous body, and a method for producing a copper porous composite member .

In order to solve such problems and achieve the above object, the copper porous body of the present invention is a copper porous body having a three-dimensional network structure skeleton, and has a porosity of 50% or more and 90%. % Normalized conductivity σ _N defined by dividing the conductivity of the copper porous body measured by the four probe method by the apparent density ratio of the copper porous body. Is 20% IACS or more.

According to the copper porous body having this configuration, even when the porosity is high within the range of 50% or more and 90% or less, the conductivity of the copper porous body measured by the four-terminal method is obtained by the copper porous body. Since the porosity normalized conductivity σ _N defined by dividing by the apparent density ratio is 20% IACS or more, it has excellent conductivity and is particularly suitable for a conductive member. Moreover, since heat conduction is carried out by free electrons as in the case of electrical conduction, the conductivity is secured at the same time as the conductivity is secured. Therefore, the copper porous body of the present invention is excellent in thermal conductivity and is particularly suitable for a heat transfer member.

Here, in the copper porous body of the present invention, it is preferable that a redox layer is formed on the surface of the skeleton.
In this case, since the redox layer is formed on the surface of the skeleton, irregularities are formed on the surface and the specific surface area is increased. For example, various properties such as heat exchange efficiency through the porous skeleton surface are greatly improved. It becomes possible to improve. Further, by performing the oxidation-reduction treatment, the porosity normalized conductivity σ _N can be further improved.

Moreover, in the copper porous body of this invention, the said frame | skeleton part may be made into the sintered compact of at least one or both of the copper powder and copper fiber which consist of copper or a copper alloy.
In this case, a copper porous body having a porosity of 50% or more and 90% or less can be obtained by adjusting the filling rate of copper powder and copper fiber made of copper or copper alloy.

Furthermore, in the copper porous body of the present invention, the copper fiber has a diameter R in the range of 0.02 mm to 1.0 mm, and a ratio L / R of the length L to the diameter R of 4 to 2500. It is preferable to be within the following range.
In this case, the diameter R of the copper fiber 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 in the range of 4 or more and 2500 or less. Sufficient voids are secured between the fibers, the shrinkage rate during sintering can be suppressed, the porosity can be increased, and the dimensional accuracy is excellent.

In the copper porous body of the present invention, it is preferable that at least one or both of the copper powder and the copper fiber are integrally bonded with the redox layers formed on the surfaces.
In this case, since the redox layers are integrally bonded to each other in at least one or both of the copper powder and the copper fiber, the bonding strength is excellent. Moreover, copper fiber and copper powder will be couple | bonded firmly, and electroconductivity and thermal conductivity can also be improved.

The copper porous composite member of the present invention is characterized by comprising a joined body of a member main body and the above-mentioned copper porous body.
According to the copper porous composite member having this configuration, since it is a joined body of the copper porous body and the member main body excellent in conductivity and thermal conductivity, the copper porous composite member has excellent conductivity. And can exhibit thermal conductivity.

Here, in the copper porous composite member of the present invention, the joint surface of the member main body with the copper porous body is composed of copper or a copper alloy, and the joint portion between the copper porous body and the member main body. Is preferably a sintered layer.
In this case, since the joining portion between the copper porous body and the member main body is a sintered layer, the copper porous body and the member main body are firmly joined, and the copper porous composite Excellent strength, conductivity, thermal conductivity, etc. can be obtained as a member.

Moreover, the method for producing a copper porous body of the present invention is a method for producing a copper porous body for producing the above-mentioned copper porous body, wherein the holding temperature is maintained in an oxidizing atmosphere with respect to the skeleton portion of the three-dimensional network structure. By performing oxidation treatment under conditions of 500 ° C. or more and 1050 ° C. or less, and performing reduction treatment under conditions of holding temperature of 500 ° C. or more and 1050 ° C. or less in a reducing atmosphere, the porosity normalized conductivity σ _{N is set} to 20% IACS or more. It is characterized by doing.

According to the method for producing a copper porous body having this configuration, the skeletal portion of the three-dimensional network structure is subjected to oxidation treatment and reduction treatment under the above-described conditions, thereby improving conductivity and standardizing porosity. The conductivity σ _N can be set to 20% IACS or more.

Further, the method for producing a copper porous body of the present invention is a method for producing a copper porous body for producing the above-mentioned copper porous body, wherein at least one or both of the copper powder and the copper fibers are oxidized in an atmosphere. And at least one or both of the copper powder and the copper fiber by performing an oxidation treatment at a holding temperature of 500 ° C. or more and 1050 ° C. or less and performing a reduction treatment at a holding temperature of 500 ° C. or more and 1050 ° C. or less in a reducing atmosphere. The skeleton portion made of the sintered body is formed, and the porosity normalized conductivity σ _N is 20% IACS or more.

According to the method for producing a copper porous body having this configuration, at least one or both of the copper powder and the copper fiber are subjected to an oxidation treatment and a reduction treatment under the above-described conditions. The skeleton portion made of at least one or both of the sintered bodies can be formed, and a copper porous body made of the sintered body can be obtained. Further, the conductivity can be improved, and the porosity normalized conductivity σ _N can be set to 20% IACS or more.

  The method for producing a copper porous composite member of the present invention is a method for producing a copper porous composite member for producing a copper porous composite member comprising a joined body of a member main body and a copper porous body, wherein the copper porous member described above is used. It has the joining process which joins the copper porous body manufactured by the manufacturing method of a solid body, and the said member main body, It is characterized by the above-mentioned.

  According to the manufacturing method of the copper porous composite member having this configuration, the copper porous body manufactured by the above-described manufacturing method of the copper porous body is provided, and the copper porous having excellent conductivity and thermal conductivity. A composite member can be manufactured. In addition, as a member main body, a board, a rod, a pipe | tube, etc. are mentioned, for example.

Here, in the method for producing a copper porous composite member of the present invention, a joining surface to which the copper porous body is joined in the member body is made of copper or a copper alloy, and the copper porous body It is preferable to join the member main body by sintering.
In this case, the member main body and the copper porous body can be integrated by sintering, and a copper porous composite member having excellent characteristic stability can be manufactured.

  According to the present invention, even if the porosity is high, the copper porous body has sufficient conductivity and thermal conductivity and is particularly suitable as a conductive member and a heat transfer member, and the copper porous body is a member. A copper porous composite member bonded to a main body, a method for producing a copper porous body, and a method for producing a copper porous composite member can be provided.

It is an expansion schematic diagram of the copper porous body which is 1st embodiment of this invention. It is a flowchart which shows an example of the manufacturing method of the copper porous body shown in FIG. It is explanatory drawing which shows the manufacturing process which manufactures the copper porous body shown in FIG. It is external appearance explanatory drawing of the copper porous composite member which is 2nd embodiment of this invention. It is a flowchart which shows an example of the manufacturing method of the copper porous composite member shown in FIG. It is an external view of the copper porous composite member which is other embodiment of this invention. It is an external view of the copper porous composite member which is other embodiment of this invention. It is an external view of the copper porous composite member which is other embodiment of this invention. It is an external view of the copper porous composite member which is other embodiment of this invention. It is an external view of the copper porous composite member which is other embodiment of this invention. It is an external view of the copper porous composite member which is other embodiment of this invention.

  Hereinafter, a copper porous body, a copper porous composite member, a copper porous body manufacturing method, and a copper porous composite member manufacturing method according to embodiments of the present invention will be described with reference to the accompanying drawings. .

(First embodiment)
First, the copper porous body 10 which is 1st embodiment of this invention is demonstrated with reference to FIGS. 1-3.
The copper porous body 10 which is this embodiment has the frame | skeleton part 12 in which the some copper fiber 11 was sintered as shown in FIG.

Here, the copper fiber 11 is made of copper or a copper 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 and 2500. Within the following range. In this embodiment, the copper fiber 11 is comprised by C1020 (oxygen-free copper), for example.
In the present embodiment, the copper fiber 11 is given a shape such as twisting or bending. Further, in the copper porous body 10 is this embodiment, the apparent density ratio D _A is 0.50 or less of the true density D _T of the copper fibers 11. The shape of the copper fibers 11, to the extent that the apparent density ratio D _A is 0.50 or less of the true density D _T of the copper fibers 11, straight, but optionally including curved, at least one copper fibers 11 If a part that has been given a predetermined shape by twisting or bending is used for the part, the gap between the fibers can be formed three-dimensionally and isotropically. This leads to an improvement in the isotropy of various characteristics such as heat transfer characteristics and conductivity of the body 10.

The copper fiber 11 is adjusted to a predetermined circle-equivalent diameter R by a drawing method, a coil cutting method, a wire cutting method, a melt spinning method, and the length is further adjusted to satisfy a predetermined L / R. Then, it is manufactured by cutting.
Here, the circle-converted diameter R is a value calculated based on the cross-sectional area A of each fiber, and is defined by the following equation assuming that it is a perfect circle regardless of the cross-sectional shape.
R = (A / π) ^1/2 × 2

Moreover, in the copper porous body 10 which is this embodiment, the oxidation reduction layer is formed in the surface of the frame | skeleton part 12 (copper fiber 11), and in the coupling | bond part of copper fibers 11 and 11, mutual surface The redox layers formed on each other are bonded together.
The redox layer has a porous structure, and has fine irregularities on the surface of the skeleton 12 (copper fibers 11). Thereby, the specific surface area of the whole copper porous body 10 shall be 0.01 m < ² > / g or more.

And in the copper porous body 10 which is this embodiment, the porosity P shall be in the range of 50% or more and 90% or less, and the electrical conductivity σ _P of the copper porous body 10 measured by the four-terminal method, copper porous body 10 porosity standards influencing for good conductivity, which is defined by dividing the apparent density ratio _{D a} of σ _N (% IACS) is a 20% IACS or more. In addition, the porosity normalized conductivity σ _N is calculated by the following equation, and the apparent density ratio D _A and the porosity P are respectively calculated by the following equations.
σ _N = σ _P × (1 / D _A )
D _A = m / (V × D _T )
P (%) = (1− (m / (V × D _T ))) × 100
Here, m: mass of copper porous body 10 (g), V: volume of copper porous body 10 (cm ³ ), D _T : true density of copper fibers 11 constituting copper porous body 10 (g / cm ³ )

Next, the manufacturing method of the copper porous body 10 which is this embodiment is demonstrated with reference to the flowchart of FIG. 2, the process drawing of FIG.
First, as shown in FIG. 3, the copper fibers 11 are spread and filled from the spreader 31 into the stainless steel container 32, and the copper fibers 11 are stacked (copper fiber stacking step S01).
Here, in the copper fibers laminating step S01, a bulk density D _P after filling is stacked a plurality of copper fibers 11 to be equal to or less than 50% of the true density D _T of the copper fibers 11. In addition, in this embodiment, since shape provision processing, such as a twist process and a bending process, is given to the copper fiber 11, a three-dimensional and isotropic space | gap is ensured between the copper fibers 11 at the time of lamination | stacking. become.

Next, the copper fiber 11 bulk-filled in the stainless steel container 32 is subjected to oxidation reduction treatment (oxidation reduction treatment step S02).
In this oxidation-reduction treatment step S02, as shown in FIGS. 2 and 3, an oxidation treatment step S21 for carrying out the oxidation treatment of the copper fibers 11, and a reduction treatment step for reducing and sintering the oxidized copper fibers 11 S22.

In this embodiment, as shown in FIG. 3, the stainless steel container 32 filled with the copper fibers 11 is charged into a heating furnace 33 and heated in an oxidizing atmosphere to oxidize the copper fibers 11 (oxidation process step). S21). By this oxidation treatment step S21, an oxide layer having a thickness of 1 μm or more and 100 μm or less, for example, is formed on the surface of the copper fiber 11.
The conditions of the oxidation treatment step S21 in the present embodiment are set such that the holding temperature is 500 ° C. or higher and 1050 ° C. or lower and the holding time is 5 minutes or longer and 300 minutes or shorter.

Here, when the holding temperature in the oxidation treatment step S <b> 21 is less than 500 ° C., the oxide layer may not be sufficiently formed on the surface of the copper fiber 11. On the other hand, when the holding temperature in the oxidation treatment step S <b> 21 exceeds 1050 ° C., the oxidation may progress to the inside of the copper fiber 11.
From the above, in this embodiment, the holding temperature in the oxidation treatment step S21 is set to 500 ° C. or higher and 1050 ° C. or lower. In order to reliably form the oxide layer on the surface of the copper fiber 11, it is preferable that the lower limit of the holding temperature in the oxidation treatment step S21 is 600 ° C. or higher and the upper limit of the holding temperature is 1000 ° C. or lower.

Moreover, when the retention time in the oxidation treatment step S <b> 21 is less than 5 minutes, the oxide layer may not be sufficiently formed on the surface of the copper fiber 11. On the other hand, when the holding time in the oxidation treatment step S <b> 21 exceeds 300 minutes, the oxidation may progress to the inside of the copper fiber 11.
From the above, in this embodiment, the holding time in the oxidation treatment step S21 is set within a range of 5 minutes or more and 300 minutes or less. In addition, in order to form an oxide layer reliably on the surface of the copper fiber 11, it is preferable that the minimum of the retention time in oxidation treatment process S21 shall be 10 minutes or more. Moreover, in order to suppress reliably oxidizing to the inside of the copper fiber 11, it is preferable to make the upper limit of the retention time in oxidation treatment process S21 into 100 minutes or less.

Next, in this embodiment, as shown in FIG. 3, after performing the oxidation treatment step S21, the stainless steel container 32 filled with the copper fibers 11 is charged into the heating furnace 34 and heated in a reducing atmosphere. Then, the oxidized copper fibers 11 are reduced to form a redox layer, and the copper fibers 11 are joined together to form the skeleton part 12 (reduction treatment step S22).
The conditions of the reduction treatment step S22 in the present embodiment are such that the atmosphere is a mixed gas atmosphere of argon and hydrogen, the holding temperature is 500 ° C. or higher and 1050 ° C. or lower, and the holding time is 5 minutes or longer and 300 minutes or shorter. .

Here, when the holding temperature in the reduction treatment step S <b> 22 is less than 500 ° C., the oxide layer formed on the surface of the copper fiber 11 may not be sufficiently reduced. On the other hand, when the holding temperature in the reduction treatment step S22 exceeds 1050 ° C., it is heated to the vicinity of the melting point of copper, and there is a possibility that the strength and the porosity are lowered.
From the above, in this embodiment, the holding temperature in the reduction treatment step S22 is set to 500 ° C. or higher and 1050 ° C. or lower. In order to reliably reduce the oxide layer formed on the surface of the copper fiber 11, the lower limit of the holding temperature in the reduction treatment step S22 is preferably set to 600 ° C. or higher. Moreover, in order to suppress reliably the fall of intensity | strength and a porosity, it is preferable to make the upper limit of the retention temperature in reduction process process S22 into 1000 degrees C or less.

Further, when the holding time in the reduction treatment step S22 is less than 5 minutes, the oxide layer formed on the surface of the copper fiber 11 may not be sufficiently reduced, and the sintering may be insufficient. . On the other hand, when the holding time in the reduction treatment step S22 exceeds 300 minutes, the thermal shrinkage due to sintering increases and the strength may decrease.
From the above, in this embodiment, the holding time in the reduction treatment step S22 is set within a range of 5 minutes or more and 300 minutes or less. In order to surely reduce the oxide layer formed on the surface of the copper fiber 11 and sufficiently advance the sintering, the lower limit of the holding temperature in the reduction treatment step S22 is preferably set to 10 minutes or more. Moreover, in order to suppress reliably the heat shrinkage and strength reduction by sintering, it is preferable that the upper limit of the holding time in the reduction treatment step S22 is 100 minutes or less.

By the oxidation treatment step S21 and the reduction treatment step S22, an oxidation reduction layer is formed on the surface of the copper fiber 11 (frame portion 12), and irregularities having a specific microporous structure are generated. That is, the redox layer 12 has a porous structure, and fine irregularities are generated on the surface of the copper fiber 11. Thereby, the specific surface area of the whole copper porous body 20 is 0.01 m < ² > / g or more.
Moreover, an oxide layer is formed on the surface of the copper fiber 11 by the oxidation treatment step S21, and the plurality of copper fibers 11 are cross-linked by the oxide layer. Thereafter, by performing the reduction treatment step S22, the oxide layer formed on the surface of the copper fiber 11 is reduced to form the above-described oxidation-reduction layer, and the oxidation-reduction layers are bonded to each other. The fibers 11 are sintered to form the skeleton part 12.

According to the manufacturing method described above, the copper fibers 11 and 11 are sintered to form the skeleton portion 12, and a redox layer is formed on the surface of the skeleton portion 12 (copper fiber 11). Furthermore, the above-mentioned porosity normalized conductivity σ _N is 20% IACS or more. Thereby, the copper porous body 10 which is this embodiment is manufactured.

According to the copper porous body 10 of the present embodiment configured as described above, the porosity P is as high as 50% or more and 90% or less, and the porosity normalized conductivity σ _N is 20%. % IACS or more, it is excellent in conductivity and thermal conductivity, and has excellent characteristics as a conductive member and a heat transfer member.

Further, according to the copper porous body 10 of the present embodiment, since the redox layer is formed on the surface of the skeleton part 12, the specific surface area is formed by forming irregularities having a microporous structure peculiar to the surface. Thus, for example, various characteristics such as heat exchange efficiency through the porous skeleton surface can be greatly improved. Further, by performing the oxidation-reduction treatment, the porosity normalized conductivity σ _N can be further improved.
Furthermore, in this embodiment, since the redox layers formed on the surfaces of the copper fibers 11 are bonded together in the bonding portion between the copper fibers 11, the bonding strength is excellent.

  Further, according to the copper porous body 10 of the present embodiment, 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, Since the skeleton part 12 is formed by sintering the copper fiber 11 within the range of 2500 or less, a sufficient gap is secured between the copper fibers 11 and the shrinkage rate during sintering The porosity is high and the dimensional accuracy is excellent.

In the present embodiment, 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 in the range of 4 to 2500. copper fibers 11, since the bulk density D _P is provided with a copper fiber lamination step S01 of stacked so that more than 50% of the true density D _T of the copper fibers 11, ensuring a gap between the copper fibers 11 to each other It is possible to suppress shrinkage. Thereby, the copper porous body 10 with high porosity and excellent dimensional accuracy can be manufactured.

Here, when the diameter R of the copper fibers 11 is less than 0.02 mm, the bonding area between the copper fibers 11 is small, and the sintered strength may be insufficient. On the other hand, when the diameter R of the copper fibers 11 exceeds 1.0 mm, the number of contacts with which the copper fibers 11 are in contact with each other is insufficient, and the sintering strength may be insufficient.
From the above, in this embodiment, the diameter R of the copper fiber 11 is set in the range of 0.02 mm or more and 1.0 mm or less. In order to further improve the strength, the lower limit of the diameter R of the copper fiber 11 is preferably 0.05 mm or more, and the upper limit of the diameter R of the copper fiber 11 is preferably 0.5 mm or less.

Further, when the ratio L / R of the length L and the diameter R of the copper fibers 11 is less than 4, the bulk density D _P and less than 50% of the true density D _T copper fibers 11 when stacked It is difficult to obtain a copper porous body 10 having a high porosity P. On the other hand, when the ratio L / R between the length L and the diameter R of the copper fiber 11 exceeds 2500, the copper fiber 11 cannot be uniformly dispersed, and the copper porous body 10 having a uniform porosity. May be difficult to obtain.
From the above, in this embodiment, the ratio L / R between the length L and the diameter R of the copper fiber 11 is set in the range of 4 or more and 2500 or less. In order to further improve the porosity, the lower limit of the ratio L / R between the length L and the diameter R of the copper fiber 11 is preferably 10 or more. Moreover, in order to obtain the copper porous body 10 with the uniform porosity P reliably, it is preferable that the ratio L / R upper limit of the length L of the copper fiber 11 and the diameter R is 500 or less.

Moreover, according to the manufacturing method of the copper porous body which is this embodiment, since the oxidation treatment process S21 which oxidizes the copper fiber 11 and the reduction treatment process S22 which reduces the oxidized copper fiber 11 are provided. A redox layer can be formed on the surface of the copper fiber 11 (skeleton part 12). In addition, the porosity normalized conductivity σ _N can be set to 20% IACS or more by the oxidation treatment step S21 and the reduction treatment step S22.

(Second embodiment)
Next, the copper porous composite member 100 which is 2nd embodiment of this invention is demonstrated with reference to attached drawing.
In FIG. 4, the copper porous composite member 100 which is this embodiment is shown. The copper porous composite member 100 includes a copper plate 120 (member main body) made of copper or a copper alloy, and a copper porous body 110 bonded to the surface of the copper plate 120.

Here, the copper porous body 110 according to the present embodiment is obtained by sintering a plurality of copper fibers to form a skeleton, as in the first embodiment. Here, the copper fiber is made of copper or a copper 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 or less. It is within the range. In the present embodiment, the copper fiber is made of, for example, C1020 (oxygen-free copper).
In the present embodiment, the copper fiber is given a shape such as twisting or bending. Further, in the copper porous body 110 is a present embodiment, the apparent density ratio D _A is less 51% of the true density D _T of copper fibers.

Furthermore, in this embodiment, a redox layer is formed by performing redox treatment (oxidation treatment and reduction treatment) on the surfaces of the copper fibers (skeleton part) and the copper plate 120 constituting the copper porous body 110 as described later. As a result, fine irregularities are formed on the surfaces of the copper fibers (skeleton part) and the copper plate 120. In the present embodiment, the specific surface area of the entire copper porous body 110 is set to 0.01 m ² / g or more.
Moreover, in the joint part of the copper fiber which comprises the copper porous body 110, and the surface of the copper plate 120, the oxidation reduction layer formed in the surface of the copper fiber and the oxidation reduction layer formed in the surface of the copper plate are united. Are connected.

And in the copper porous body 110 which concerns on this embodiment, the porosity P shall be in the range of 50% or more and 90% or less, and the electrical conductivity (sigma) _P of the copper porous body 110 measured by the 4 terminal method is set. copper porous body 110 porosity standards influencing for good conductivity sigma _N defined by dividing the apparent density ratio D _a of is the 20% IACS or more.

Next, a method for manufacturing the copper porous composite member 100 according to the present embodiment will be described with reference to the flowchart of FIG.
First, the copper plate 120 which is a member main body is prepared (copper plate arrangement | positioning process S100). Next, copper fibers are dispersed and arranged on the surface of the copper plate 120 (copper fiber lamination step S101). Here, in the copper fibers lamination step S101, bulk density D _P is stacked a plurality of copper fibers to be equal to or less than 50% of the true density D _T of copper fibers.

  Next, the copper fibers stacked and arranged on the surface of the copper plate 120 are sintered to form the copper porous body 110, and the copper porous body 110 and the copper plate 120 are bonded (sintering step S102 and joining step S103). ). In the sintering step S102 and the joining step S103, as shown in FIG. 5, the oxidation treatment step S121 for performing the oxidation treatment of the copper fiber and the copper plate 120 and the oxidized copper fiber and the copper plate 120 are reduced and sintered. Reduction processing step S122.

In the present embodiment, the copper plate 120 on which the copper fibers are laminated is placed in a heating furnace and heated in an oxidizing atmosphere to oxidize the copper fibers (oxidation treatment step S121). By this oxidation treatment step S121, an oxide layer having a thickness of 1 μm or more and 100 μm or less is formed on the surfaces of the copper fiber and the copper plate 120, for example.
Here, the conditions of the oxidation treatment step S121 in the present embodiment are that the holding temperature is 500 ° C. or higher and 1050 ° C. or lower, desirably 600 ° C. or higher and 1000 ° C. or lower, and the holding time is 5 minutes or longer and 300 minutes or shorter, preferably 10 It is within the range of not less than 100 minutes and not more than 100 minutes.

Next, in the present embodiment, after performing the oxidation treatment step S121, the copper plate 120 on which the copper fibers are laminated is placed in a firing furnace, heated in a reducing atmosphere, and oxidized copper fibers and the copper plate 120. The copper fiber and the copper plate 120 are combined with each other (reduction process step S122).
Here, the conditions of the reduction treatment step S122 in this embodiment are that the atmosphere is a mixed gas atmosphere of nitrogen and hydrogen, the holding temperature is 500 ° C. or higher and 1050 ° C. or lower, desirably 600 ° C. or higher and 1000 ° C. or lower, and the holding time is 5 Min. To 300 min., Preferably 10 min. To 100 min.

By the oxidation treatment step S121 and the reduction treatment step S122, a redox layer is formed on the surfaces of the copper fibers (skeleton part) and the copper plate 120, and fine irregularities are generated.
In addition, an oxide layer is formed on the surfaces of the copper fibers (skeleton) and the copper plate 120 by the oxidation treatment step S121, and the plurality of copper fibers and the copper plate 120 are cross-linked by the oxide layer. Thereafter, by performing the reduction treatment step S122, the copper fiber (skeleton part) and the oxide layer formed on the surface of the copper plate 120 are reduced, and the copper fibers are sintered through the oxidation-reduction layer, so that the skeleton part is formed. As formed, the copper porous body 110 and the copper plate 120 are bonded. Furthermore, the porosity normalized conductivity σ _{N of} the copper porous body 110 is 20% IACS or more.
The copper porous composite member 100 according to the present embodiment is manufactured by the manufacturing method as described above.

According to the copper porous composite member 100 of the present embodiment configured as described above, the porosity normalized conductivity σ _{N of} the copper porous body 110 is 20% IACS or more. In addition, the conductivity and thermal conductivity of the entire copper porous composite member 100 can be improved.

Furthermore, in this embodiment, an oxidation-reduction layer is formed on the surfaces of the copper fibers and the copper plate 120 constituting the copper porous body 110, and the specific surface area of the entire copper porous body 110 is 0.01 m ² / g or more. The porosity P is in the range of 50% or more and 90% or less, and it is possible to greatly improve various characteristics such as heat exchange efficiency and water retention.

  Moreover, in this embodiment, in the coupling | bond part of the copper fiber which comprises the copper porous body 110, and the surface of the copper plate 120, it formed in the surface of the copper plate 120 and the oxidation reduction layer formed in the surface of the copper fiber. Since the redox layer is integrally bonded, the copper porous body 110 and the copper plate 120 are firmly bonded, and the strength, conductivity and thermal conductivity of the bonding interface are excellent.

According to the manufacturing method of the copper porous composite member 100 according to the present embodiment, the copper fibers are stacked on the surface of the copper plate 120 made of copper and a copper alloy, and the sintering step S102 and the joining step S103 are simultaneously performed. Therefore, the manufacturing process can be simplified.
In addition, by performing the oxidation treatment step S121 and the reduction treatment step S122, the porosity normalized conductivity σ _N can be set to 20% IACS or more.

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 demonstrated as what manufactures a copper porous body using the manufacturing equipment shown in FIG. 3, it is not limited to this, Even if it manufactures a copper porous body using another manufacturing equipment Good.

  The atmosphere of the oxidation treatment steps S21 and S121 may be an oxidation atmosphere in which copper or a copper alloy is oxidized at a predetermined temperature. Specifically, the atmosphere is not limited to the atmosphere, but is set to 0. 1 in an inert gas (for example, nitrogen). Any atmosphere containing 5 vol% or more of oxygen may be used. Also, the atmosphere of the reduction treatment steps S22 and S122 may be any reducing atmosphere in which copper oxide is reduced to metallic copper or copper oxide is decomposed at a predetermined temperature. Specifically, hydrogen of several vol% or more is used. A nitrogen-hydrogen mixed gas, an argon-hydrogen mixed gas, a pure hydrogen gas, or an ammonia decomposition gas or a propane decomposition gas that is often used industrially can also be suitably used.

Furthermore, in this embodiment, although demonstrated as what forms the frame | skeleton part of a copper porous body by sintering copper fiber, it is not limited to this, For example, copper, such as a fiber nonwoven fabric and a metal filter A porous body is prepared, and the copper porous body is subjected to an oxidation treatment in an oxidizing atmosphere under a holding temperature of 500 ° C. or higher and 1050 ° C. or lower, and in a reducing atmosphere under a holding temperature of 500 ° C. or higher and 1050 ° C. or lower. By performing the reduction treatment, the porosity normalized conductivity σ _N may be set to 20% IACS or more.

Furthermore, in the present embodiment, the description has been made on the assumption that the redox layer is formed on the surface of the skeleton, but the present invention is not limited to this, and the redox layer may not be sufficiently formed. It is only necessary that the conductivity σ _N is 20% IACS or more.

  In the present embodiment, it has been described that copper fibers made of oxygen-free copper (JIS C1020), phosphorus deoxidized copper (JIS C1201, C1220), tough pitch copper (JIS C1100), or the like are used, but the present invention is not limited thereto. As a material of the copper fiber 11, a highly conductive copper alloy such as other Cr copper (C18200) or Cr—Zr copper (C18150) may be used.

In the second embodiment, the copper porous composite member having the structure shown in FIG. 4 has been described as an example. However, the present invention is not limited to this, and the copper having the structure as shown in FIGS. It may be a porous composite member.
Furthermore, in 2nd embodiment, although the joining method in which the sintered layer which consists of a redox layer is formed in the junction part of a copper porous body and a member main body was illustrated as a desirable method, it is limited to this. In addition, the porosity normalized conductivity σ _{N of} the copper porous body is 20% IACS or more even in various welding methods (laser welding method, resistance welding method) and the joining method by brazing using a brazing material that melts at low temperature It only has to be.

For example, as shown in FIG. 6, a copper porous composite member 200 having a structure in which a plurality of copper tubes 220 are inserted into a copper porous body 210 as a member main body may be used.
Alternatively, as shown in FIG. 7, a copper porous composite member 300 having a structure in which a copper tube 320 curved in a U shape as a member main body is inserted into a copper porous body 310 may be used.

Furthermore, as shown in FIG. 8, the copper porous composite member 400 of the structure which joined the copper porous body 410 to the internal peripheral surface of the copper pipe 420 which is a member main body may be sufficient.
Moreover, as shown in FIG. 9, the copper porous composite member 500 of the structure which joined the copper porous body 510 to the outer peripheral surface of the copper tube 520 which is a member main body may be sufficient.

Furthermore, as shown in FIG. 10, a copper porous composite member 600 having a structure in which a copper porous body 610 is bonded to the inner peripheral surface and the outer peripheral surface of a copper tube 620 that is a member main body may be used.
Moreover, as shown in FIG. 11, the copper porous composite member 700 of the structure which joined the copper porous body 710 to both surfaces of the copper plate 720 which is a member main body may be sufficient.

  Below, the result of the confirmation experiment performed in order to confirm the effect of this invention is demonstrated.

Example 1
Various porous bodies manufactured by the materials and manufacturing methods shown in Table 1 were prepared. First, the porosity before heat treatment and the porosity normalized conductivity were measured. Thereafter, oxidation treatment and reduction treatment were performed under the conditions described in Table 1, and the porosity and porosity normalized conductivity after the oxidation treatment and reduction treatment were measured. In addition, the porosity and the porosity normalized conductivity were measured as follows. The evaluation results are shown in Table 1.

(Porosity)
The true density D _T (g / cm ³ ) was measured by an underwater method using a precision balance, and the porosity P was calculated by the following equation. The mass of the copper porous body was m (g), and the volume of the copper porous body was V (cm ³ ).
Porosity P (%) = (1− (m / (V × D _T ))) × 100

(Porosity normalized conductivity)
Using a sample cut into a plate shape having a width of 30 mm, a length of 200 mm, and a thickness of 5 mm, a voltage terminal interval of 150 mm and a measurement current of 0.5 A using a micro-ohm high tester 3227 manufactured by Hioki Electric Co., Ltd. in accordance with JIS C2525. The electrical conductivity σ _P (% IACS) was measured by the four-terminal method under the following conditions. And the porosity normalized electrical conductivity (sigma) _N was computed with the following formula | equation.
Porosity normalized conductivity σ _N (% IACS) = σ _P × (1 / D _A )

In Invention Example 1-4, in which the oxidation treatment and the reduction treatment were performed under the conditions specified in the present invention, the porosity P was in the range of 50% or more and 90% or less, and the porosity normalized conductivity was 20%. % IACS was exceeded.
On the other hand, in Comparative Example 1 where the temperature condition for the oxidation treatment is low and Comparative Example 2 where the temperature condition for the reduction treatment is low, the conductivity is not sufficiently improved even after the oxidation treatment and the reduction treatment, The porosity normalized conductivity σ _N was less than 20% IACS.

(Example 2)
Using the copper powder shown in Table 2, oxidation-reduction treatment was performed under the conditions shown in Table 2 to produce a copper porous body. About the obtained copper porous body, the porosity and the porosity normalized electrical conductivity were measured. The porosity and the porosity normalized conductivity were measured by the same method as in Example 1. The evaluation results are shown in Table 2.

In Invention Examples 11-14 in which the oxidation treatment and the reduction treatment were performed under the conditions specified in the present invention, the porosity P was in the range of 50% to 90% and the porosity normalized conductivity was 20%. % IACS was exceeded.
In contrast, in Comparative Example 11 where the temperature condition for the oxidation treatment is low and in Comparative Example 12 where the temperature condition for the reduction treatment is low, the porosity normalized conductivity σ _N is less than 20% IACS.

(Example 3)
Using the copper fibers shown in Table 3, oxidation-reduction treatment was performed under the conditions shown in Table 3 to produce a copper porous body. In addition, the fiber diameter R and the fiber length L of the copper fiber were measured by the following methods.

(Fiber diameter R)
The fiber diameter R is a circle equivalent diameter (Heywood diameter) R = (A / π) ^{1 /} calculated by image analysis based on JIS Z8827-1 using a particle analyzer “Morphology G3” manufactured by Malvern. An average value of ² × 2 was used.

(Fiber length L)
As the fiber length L of the copper fiber, a simple average value calculated by image analysis using a particle analyzer “Morphology G3” manufactured by Malvern, Inc. was used.

  About the obtained copper porous body, the porosity and the porosity normalized electrical conductivity were measured. The porosity and the porosity normalized conductivity were measured by the same method as in Example 1. The evaluation results are shown in Table 3.

In Invention Examples 21 to 26, in which the oxidation treatment and the reduction treatment were performed under the conditions specified in the present invention, the porosity P was in the range of 50% to 90%, and the porosity normalized conductivity was 20%. % IACS was exceeded.
On the other hand, in Comparative Example 21 where the temperature condition for the oxidation treatment is low and Comparative Example 22 where the temperature condition for the reduction treatment is low, the porosity normalized conductivity σ _N is less than 20% IACS.

  From the above, according to the example of the present invention, even when the porosity is high, a copper porous body having sufficient conductivity and thermal conductivity and particularly suitable as a conductive member and a heat transfer member is provided. It was confirmed that it was possible.

10, 110 Copper porous body 11 Copper fiber 12 Skeletal part 100 Copper porous composite member 120 Copper plate (member main body)

Claims (11)

A porous copper body having a three-dimensional network structure skeleton,
The porosity is in the range of 50% to 90%,
The porosity normalized conductivity σ _N defined by dividing the conductivity of the copper porous body measured by the four-terminal method by the apparent density ratio of the copper porous body is 20% IACS or more. A copper porous body characterized by having   The copper porous body according to claim 1, wherein a redox layer is formed on a surface of the skeleton portion.   3. The copper porous body according to claim 1, wherein the skeleton portion is a sintered body of at least one or both of copper powder and copper fiber made of copper or a copper alloy.   The copper fiber has a diameter R in the range of 0.02 mm to 1.0 mm, and a ratio L / R of the length L to the diameter R in the range of 4 to 2500. The copper porous body according to claim 3.   5. The copper according to claim 3, wherein at least one or both of the copper powder and the copper fiber are bonded together by oxidation-reduction layers formed on surfaces of each other. Porous body.   A copper porous composite member comprising a joined body of a member main body and the copper porous body according to any one of claims 1 to 5.   The joint surface of the member main body with the copper porous body is made of copper or a copper alloy, and the joint portion between the copper porous body and the member main body is a sintered layer. Item 7. A copper porous composite member according to Item 6. It is a manufacturing method of the copper porous body which manufactures the copper porous body according to claim 1 or 2,
A three-dimensional network structure skeleton is oxidized in an oxidizing atmosphere at a holding temperature of 500 ° C. or higher and 1050 ° C. or lower, and is reduced in a reducing atmosphere at a holding temperature of 500 ° C. or higher and 1050 ° C. or lower. The porosity normalized conductivity σ _{N is set} to 20% IACS or more. It is a manufacturing method of the copper porous body which manufactures the copper porous body according to any one of claims 3 to 5,
At least one or both of the copper powder and the copper fiber are oxidized in an oxidizing atmosphere under a holding temperature of 500 ° C. or higher and 1050 ° C. or lower and reduced in a reducing atmosphere under a holding temperature of 500 ° C. or higher and 1050 ° C. or lower. By performing, the skeleton portion formed of a sintered body of at least one or both of the copper powder and the copper fiber is formed, and the porosity normalized conductivity σ _{N is set} to 20% IACS or more. A method for producing a copper porous body. A method for producing a copper porous composite member comprising a member body and a joined body of copper porous bodies according to any one of claims 1 to 5,
A method for producing a copper porous composite member comprising a joining step of joining the copper porous body according to any one of claims 1 to 5 and the member main body.   The joining surface to which the copper porous body is joined among the member bodies is made of copper or a copper alloy, and the joining step joins the copper porous body and the member body by sintering. The method for producing a copper porous composite member according to claim 10.

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