TW201806751A - Copper porous body, copper porous composite member, method for manufacturing copper porous body, and method for manufacturing copper porous composite member - Google Patents

Abstract

A copper porous body of the present invention includes a skeleton section having a three-dimensional network structure. A porosity is ranging from 50% to 90%. A normalized conductivity [sigma]N which is normalized by porosity, a conductivity of the copper porous body measured by a four-terminal method divided by an apparent density ratio of the copper porous body, is 20%IACS or more.

Description

Copper porous body, copper porous composite member, method for manufacturing copper porous body, and method for manufacturing copper porous composite member

The present invention relates to a copper porous body made of copper or a copper alloy, a copper porous composite member in which the copper porous body is bonded to a member body, a method for manufacturing the copper porous body, and copper porous Manufacturing method of high quality composite member.

This case is based on Japanese Patent Application No. 2016-089358 filed in Japan on April 27, 2016, claiming its priority, and applying its content here.

The above-mentioned copper porous body and copper porous composite member are used as, for example, electrodes and current collectors in various batteries, members for heat exchangers, 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, it is disclosed that a three-dimensional network structure made of a material that is burned by heating is used. style (Such as urethane foam, polyethylene foam, and other continuous foamed synthetic resin foams, natural fiber cloth, rayon cloth, etc.) are coated with adhesives to form the metal powder. Or a sheet-shaped formed body made of a material (for example, pulp or wool fiber) made of a material that is burned out by heating and can form a three-dimensional network structure, such as pulp or wool fibers. Method, etc.

In addition, Patent Document 2 discloses a method for obtaining a porous material by applying electric heating to copper fibers under pressure.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 08-145592

[Patent Document 2] Japanese Patent No. 3735712

In addition, the above-mentioned copper porous body requires high electrical conductivity when used as a conductive member such as an electrode and a current collector with a high porosity and an open-cell structure, and is used as a heat exchanger member and a heat pipe. When a heat transfer member is used, excellent thermal conductivity is required.

In the copper porous bodies described in Patent Documents 1 and 2, electrical and thermal conductivity are not taken into consideration. In particular, when the porosity is high, the copper powder or copper fibers are not sufficiently bonded to each other, and as a result, they have electrical conductivity. And insufficient thermal conductivity.

The present invention has been completed on the background of the above-mentioned facts, so as to provide a copper porous body which has sufficient electrical and thermal conductivity even when the porosity is high, and is particularly suitable as a conductive member and a heat transfer member. A copper porous composite member in which a 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 are aimed at.

In order to solve the problems and achieve the aforementioned object, a copper porous system according to one aspect of the present invention has a copper porous body having a skeleton portion of a three-dimensional network structure, which is characterized in that the porosity is within a range of 50% to 90%. The conductivity of the copper porous body measured by the 4-terminal method divided by the porosity normalized conductivity σ _N specified by the apparent density ratio of the copper porous body is 20% IACS or more.

In the copper porous body thus constituted, even when the porosity is in the range of 50% to 90%, the electrical conductivity of the copper porous body measured by the 4-terminal method is divided by the copper porous body. The normalized porosity specified by the apparent density ratio and the conductivity σ _{N are} still more than 20% IACS, which is excellent in electrical conductivity, and is particularly suitable for conductive members. In addition, since thermal conduction is borne by free electrons as well as electrical conduction, thermal conductivity can be secured while ensuring electrical conductivity. Therefore, the copper porous body of the present invention is also excellent in thermal conductivity, and is particularly suitable for a heat transfer member.

Here, in the copper porous body according to the aspect of the present invention, it is preferable that a redox layer is formed on the surface of the skeleton portion.

At this time, since a redox layer is formed on the surface of the skeleton portion, unevenness is formed on the surface to increase the specific surface area, and various characteristics such as heat exchange efficiency through the porous skeleton surface can be significantly improved. In addition, by performing a redox treatment, the porosity normalized conductivity σ _N can be further improved.

In the copper porous body according to the aspect of the present invention, the sintered body of at least one or both of copper powder and copper fibers made of copper or a copper alloy may be used as the skeleton portion.

At this time, by adjusting the filling rate of copper powder and copper fibers made of copper or copper alloy, a copper porous body having a porosity of 50% to 90% can be obtained.

Furthermore, in the copper porous body according to one aspect of the present invention, it is preferable that the copper fiber has a diameter R of 0.02 mm or more and 1.0 mm or less, and a ratio L / R of the length L to the diameter R of 4 or more and 2500. Within the following range.

At this time, since the diameter R of the copper fibers 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, sufficient gaps between the copper fibers can be ensured. In addition, it can reduce the shrinkage rate during sintering, improve the porosity, and have excellent dimensional accuracy.

In the copper porous body according to the aspect of the present invention, it is preferable that the redox layers formed on the surfaces of the copper powder and the copper fiber are bonded to each other integrally. .

At this time, since the redox layers are integrally bonded to each other at a joint portion of at least one of the copper powder and the copper fiber, the bonding strength is excellent. In addition, copper fibers and copper powders are strongly bonded to each other, which also improves electrical and thermal conductivity.

A copper porous composite member according to one aspect of the present invention is characterized by a member body and a joint body with the copper porous body described above.

The copper porous composite member thus constituted is a joined body of a copper porous body and a member body having excellent electrical and thermal conductivity, and can exhibit excellent electrical conductivity and thermal conductivity of the copper porous composite member itself.

Here, in the copper porous composite member according to the aspect of the present invention, it is preferable that a joint surface between the member body and the copper porous body is made of copper or a copper alloy, and the copper porous body and the member are formed. The joint portion of the body is a sintered layer.

At this time, since the joint portion of the copper porous body and the member body is formed as a sintered layer, the copper porous body and the member body are strongly bonded, and the copper porous composite member itself can obtain excellent strength, electrical conductivity, and heat conduction. Sex, etc.

Moreover, the manufacturing method of the copper porous body of one form of this invention is the manufacturing method of the said copper porous body of the said copper porous body, It is characterized by the skeleton part of a three-dimensional network structure in an oxidizing environment and The oxidation treatment is performed under the conditions of maintaining a temperature of 500 ° C to 1050 ° C, and the reduction treatment is performed under a reducing environment and a condition of maintaining temperatures of 500 ° C to 1050 ° C, so that the porosity normalized conductivity σ _N becomes 20% IACS or more .

According to the manufacturing method of the copper porous body thus constituted, by performing oxidation treatment and reduction treatment on the skeleton portion of the three-dimensional network structure under the above conditions, the conductivity can be improved, and the porosity can be normalized. The conductivity σ _{N can} be 20 % IACS or more.

Moreover, the manufacturing method of the copper porous body of one form of this invention is a manufacturing method of the copper porous body which manufactures the said copper porous body, It is characterized by making at least one of the said copper powder and the said copper fiber or Both of them are subjected to oxidation treatment in an oxidizing environment and maintained at a temperature of 500 ° C to 1050 ° C, and subjected to reduction treatment in a reducing environment and maintained at a temperature of 500 ° C to 1050 ° C to form the aforementioned copper powder and the aforementioned The aforementioned skeleton portion composed of a sintered body of at least one or both of the copper fibers has a porosity normalized conductivity σ _N of 20% IACS or more.

According to the manufacturing method of the copper porous body thus constituted, at least one or both of the copper powder and the copper fiber are subjected to oxidation treatment and reduction treatment under the conditions described above, so that the copper powder and the copper fiber can be formed. A copper porous body made of the sintered body can be obtained from the skeleton portion made of at least one or both of the sintered bodies. In addition, the conductivity can be improved and the porosity normalized conductivity σ _{N can} be 20% IACS or more.

A method for manufacturing a copper porous composite member according to one aspect of the present invention is a method for manufacturing a copper porous composite member that manufactures a copper porous composite member composed of a joint body of a member body and a copper porous body. The method includes: A copper porous body manufactured by the above-mentioned copper porous body manufacturing method, and a joining step of joining the member body.

A method for producing a copper porous composite member having the above structure is provided with a large amount of copper produced by the method for producing a copper porous body as described above. Porous bodies can produce copper porous composite members with excellent electrical and thermal conductivity. Examples of the shape of the member body include a plate, a rod, and a tube.

Here, in the method for manufacturing a copper porous composite member according to an aspect of the present invention, it is preferable that a joint surface to be joined to the copper porous body in the member body is made of copper or a copper alloy, and the copper The porous body and the member body are joined by sintering.

In this case, the member body and the copper porous body can be integrally molded by sintering, and a copper porous composite member having excellent stability in characteristics can be manufactured.

According to the present invention, it is possible to provide a copper porous body having sufficient electrical and thermal conductivity even when the porosity is high, which is particularly suitable as a conductive member and a heat transfer member, and the copper porous body is bonded to the member body The produced copper porous composite member, a method for producing a copper porous body, and a method for producing a copper porous composite member.

10.110‧‧‧copper porous body

11‧‧‧copper fiber

12‧‧‧Frame Department

100‧‧‧ Copper porous composite member

120‧‧‧copper plate (component body)

FIG. 1 is an enlarged schematic view of a copper porous body according to the first embodiment of the present invention.

Fig. 2 is a flowchart showing an example of a method for producing the copper porous body shown in Fig. 1.

Fig. 3 is an explanatory diagram showing a manufacturing process for producing the copper porous body shown in Fig. 1.

Fig. 4 is an external view illustrating a copper porous composite member according to a second embodiment of the present invention.

FIG. 5 is a flowchart showing an example of a method for manufacturing a copper porous composite member shown in FIG. 4.

Fig. 6 is an external view of a copper porous composite member according to another embodiment of the present invention.

FIG. 7 is an external view of a copper porous composite member according to another embodiment of the present invention.

FIG. 8 is an external view of a copper porous composite member according to another embodiment of the present invention.

FIG. 9 is an external view of a copper porous composite member according to another embodiment of the present invention.

Fig. 10 is an external view of a copper porous composite member according to another embodiment of the present invention.

FIG. 11 is an external view of a copper porous composite member according to another embodiment of the present invention.

[Form of Implementing Invention]

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

(First Embodiment)

First, the copper porous body 10 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

The copper porous body 10 of this embodiment has a skeleton portion 12 obtained by sintering a plurality of copper fibers 11 as shown in FIG. 1.

Here, the copper fiber 11 is made of copper or a copper alloy, and the diameter R is in a 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 a range of 4 or more and 2500 or less. In this embodiment, the copper fiber 11 is made of, for example, C1020 (oxygen-free copper).

In this embodiment, the copper fibers 11 are shaped by twisting, bending, or the like. Moreover, in the copper porous body 10 of this embodiment, the apparent density ratio D _A is 51% or less of the true density D _T of the copper fiber 11. As for the shape of the copper fiber 11, as long as the apparent density ratio D _A is 51% or less of the true density D _T of the copper fiber 11, the shape is any one of a linear shape and a curved shape; however, if at least the copper fiber 11 is used, Partially performing a predetermined shaping process such as twisting or bending can form three-dimensionally and uniformly the shape of the spaces between the fibers. As a result, it contributes to the heat transfer characteristics of the copper porous body 10 and Uniformity of various properties such as conductivity is improved.

In addition, the copper fiber 11 is adjusted to a predetermined equivalent circle diameter R by a drawing method, a spiral cutting method, a wire cutting method, a melt spinning method, and the like, and further cut to adjust the length to meet a predetermined L / R.

Here, the equivalent circle diameter R is a value calculated based on the cross-sectional area A of each fiber, and is assumed to be a perfect circle regardless of the cross-sectional shape, and is defined by the following formula.

R = (A / π) ^1/2 × 2

In the copper porous body 10 of this embodiment, a redox layer is formed on the surface of the skeleton portion 12 (copper fiber 11), and a redox layer is formed on the surfaces of the copper fibers 11 and 11 at a joint portion. The layers are integrated with each other.

In addition, this redox layer system forms a porous structure, and fine irregularities are formed on the surface of the skeleton portion 12 (copper fiber 11). As a result, the specific surface area of the entire copper porous body 10 becomes 0.01 m ² / g or more. The specific surface area of the entire copper porous body 10 is preferably 0.03 m ² / g or more, but is not limited thereto.

In the copper porous body 10 of this embodiment, the porosity P is in the range of 50% to 90%, and the electrical conductivity σ _P of the copper porous body 10 measured by the 4-terminal method is divided by copper. The porosity normalized conductivity σ _N (% IACS) prescribed by the apparent density ratio D _{A of} the porous body 10 is 20% IACS or more. The porosity normalized conductivity σ _N , the apparent density ratio D _A , and the porosity P are calculated by the following formulas, respectively.

σ _N = σ _P × (1 / D _A )

D _A = m / (V × D _T )

P (%) = (1- (m / (V × D _T ))) × 100

Herein, m: mass (g) of the porous body 10 Cu, V: volume (cm ³⁾ of the porous copper body 10, D _T: copper porous body 10 constituted of copper fibers true density of 11 (g / cm ³ )

The porosity P is preferably within a range of 70% to 90%, but is not limited thereto.

Next, the manufacturing method of the copper porous body 10 of this embodiment is demonstrated with reference to the flowchart of FIG. 2 and the step chart of FIG.

First, as shown in FIG. 3, the copper fibers 11 are dispersed and filled in a stainless steel container 32 by a spreader 31, and the copper fibers 11 are laminated (copper fiber lamination step S01).

Here, in this copper fiber lamination step S01, a plurality of copper fibers 11 are laminated and arranged such that the bulk density D _P after filling is 50% or less of the true density D _T of the copper fibers 11. In addition, in this embodiment, since the copper fibers 11 are subjected to a shaping process such as twisting or bending, the three-dimensional and uniform voids can be ensured between the copper fibers 11 during lamination.

Next, the copper fibers 11 filled in the stainless steel container 32 are subjected to a redox treatment (redox treatment step S02).

In this oxidation-reduction treatment step S02, as shown in FIG. 2 and FIG. 3, it is provided with: an oxidation treatment step S21, which performs the oxidation treatment of the copper fiber 11; and a reduction treatment step S22, which is an oxidation-treated copper The fibers 11 are reduced and sintered.

In this embodiment, as shown in FIG. 3, a stainless steel container 32 filled with copper fibers 11 is placed in a heating furnace 33, and the copper fibers 11 are subjected to an oxidation treatment by heating in an oxidizing environment (oxidation treatment step S21). ). By this oxidation treatment step S21, the surface of the copper fiber 11 is An oxide layer having a thickness of, for example, 1 μm or more and 100 μm or less is formed.

The conditions of the oxidation treatment step S21 in the present embodiment are an atmospheric environment (atmospheric environment (a)), a holding temperature of 500 ° C. or higher and 1050 ° C. or lower, and a holding time of 5 minutes or more and 300 minutes or less.

Here, when the holding temperature in the oxidation treatment step S21 is less than 500 ° C., an 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 S21 exceeds 1050 ° C., the inside of the copper fiber 11 may be oxidized.

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 addition, in order to form an oxide layer on the surface of the copper fiber 11 reliably, the lower limit of the holding temperature in the oxidation treatment step S21 is preferably set to 600 ° C or higher, and the upper limit of the holding temperature is set to 1000 ° C or lower.

When the holding time in the oxidation treatment step S21 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 S21 exceeds 300 minutes, the inside of the copper fiber 11 may be oxidized.

As described above, in this embodiment, the holding time in the oxidation treatment step S21 is set to a range of 5 minutes or more and 300 minutes or less. In addition, in order to reliably form an oxide layer on the surface of the copper fiber 11, the lower limit of the holding time in the oxidation treatment step S21 is preferably set to 10 minutes or more. In addition, in order to reliably suppress the inside of the copper fiber 11 When oxidation is performed, the upper limit of the holding time in the oxidation treatment step S21 is preferably set to 100 minutes or less.

Next, in this embodiment, as shown in FIG. 3, after the oxidation treatment step S21 is performed, the stainless steel container 32 filled with the copper fiber 11 is put into a heating furnace 34, and heated in a reducing environment, and the oxidized The copper fibers 11 are subjected to a reduction treatment to form a redox layer, and the copper fibers 11 are bonded to each other to form a skeleton portion 12 (reduction treatment step S22).

The conditions of the reduction processing step S22 in this embodiment are a mixed gas environment (Ar + H ₂ environment (b)) of argon and hydrogen, a holding temperature of 500 ° C. or higher and 1050 ° C. or lower, and a holding time of 5 minutes or more. Within 300 minutes.

Here, when the holding temperature in the reduction processing step S22 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 a temperature close to the melting point of copper, and the strength and porosity may decrease.

From the above, in this embodiment, the holding temperature in the reduction process step S22 is set to 500 ° C or higher and 1050 ° C or lower. In addition, in order to surely 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. In addition, in order to reliably suppress the decrease in strength and porosity, it is preferable to set the upper limit of the holding temperature in the reduction treatment step S22 to 1000 ° C. or lower.

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 there may be insufficient sintering. On the other hand, when the holding time in the reduction processing step S22 exceeds 300 minutes, there is a possibility that the thermal shrinkage due to sintering becomes large and the strength decreases.

From the above, in this embodiment, the holding time in the reduction processing step S22 is set to a range of 5 minutes or more and 300 minutes or less. In addition, in order to surely reduce the oxide layer formed on the surface of the copper fiber 11 and sufficiently perform sintering, it is preferable to set the lower limit of the holding temperature in the reduction treatment step S22 to 10 minutes or more. In addition, in order to reliably suppress thermal shrinkage or reduction in strength due to sintering, it is preferable to set the upper limit of the holding time in the reduction treatment step S22 to 100 minutes or less.

By this oxidation treatment step S21 and reduction treatment step S22, a redox layer is formed on the surface of the copper fiber 11 (skeleton part 12), and the unevenness | corrugation which has a unique fine porous structure is produced. That is, the redox layer 12 has a porous structure, and fine unevenness is generated on the surface of the copper fiber 11. Thereby, the specific surface area of the whole copper porous body 20 becomes 0.01 m <^2> / g or more.

In addition, an oxide layer is formed on the surface of the copper fiber 11 by the oxidation treatment step S21, whereby the oxide layer cross-links the plurality of copper fibers 11 to each other. Thereafter, by performing a reduction treatment step S22, the oxide layer formed on the surface of the copper fiber 11 is reduced to form the above-mentioned redox layer, and this redox layer is bonded to each other, whereby the copper fibers 11 are sintered to form each other骨 部 12。 The skeleton portion 12.

According to the manufacturing method described above, the copper fibers 11 and 11 are sintered with each other to form the skeleton portion 12, and at the same time, a redox layer is formed on the surface of the skeleton portion 12 (copper fiber 11). The above-mentioned porosity normalized conductivity σ _{N is} 20% IACS or more. Thereby, the copper porous body 10 of this embodiment is completed.

According to the copper porous body 10 of the present embodiment configured as described above, since the porosity P is in the range of 50% to 90%, and the porosity is normalized, the conductivity σ _{N is} 20% IACS or more, and the electrical conductivity and thermal conductivity are Excellent, with excellent characteristics as a conductive member and a heat transfer member.

In addition, according to the copper porous body 10 of this embodiment, since the redox layer is formed on the surface of the skeleton portion 12, the specific surface area becomes larger by forming irregularities having a unique fine porous structure on the surface, which can greatly improve Various characteristics such as heat exchange efficiency on the surface of the porous body skeleton. In addition, by performing a redox treatment, the porosity normalized conductivity σ _N can be further improved.

Furthermore, in the present embodiment, since the redox layers formed on the surfaces of the copper fibers 11 are bonded together, the bonding strength is excellent.

In addition, according to the copper porous body 10 of the present embodiment, the ratio L / R of the length L to the diameter R is in the range of 4 to 2500 because the diameter R is in the range of 0.02 mm to 1.0 mm. The inner copper fibers 11 are sintered to form the skeleton portion 12. Therefore, a sufficient space between the copper fibers 11 can be ensured, the shrinkage rate during sintering can be suppressed, the porosity is high, and the dimensional accuracy is excellent.

Furthermore, in this embodiment, the length L is provided in a range where the bulk density D _P is 50% or less of the true density D _T of the copper fiber 11 and the diameter R is 0.02 mm or more and 1.0 mm or less. The copper fiber lamination step S01 of the copper fibers 11 in a range of the ratio L / R to the diameter R of 4 or more and 2500 or less can ensure a space between the copper fibers 11 and 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, there is a possibility that the bonding area between the copper fibers 11 is small and the sintering strength is insufficient. On the other hand, when the diameter R of the copper fibers 11 exceeds 1.0 mm, the number of contacts where the copper fibers 11 are in contact with each other may be insufficient, and the sintering strength may still be insufficient.

As described above, in the present embodiment, the diameter R of the copper fiber 11 is set within a range of 0.02 mm or more and 1.0 mm or less. In order to further increase the strength, the lower limit of the diameter R of the copper fiber 11 is preferably set to 0.05 mm or more, and the upper limit of the diameter R of the copper fiber 11 is preferably set to 0.5 mm or less.

In addition, when the ratio L / R of the length L to the diameter R of the copper fiber 11 is less than 4, it is difficult to make the bulk density D _P be 50% or less of the true density D _T of the copper fiber 11 when performing the lamination configuration, and it is not easy. The copper porous body 10 having a high porosity P may be obtained. On the other hand, when the ratio L / R of the length L to the diameter R of the copper fiber 11 exceeds 2500, the copper fiber 11 cannot be uniformly dispersed, and there is a concern that it is difficult to obtain a copper porous body 10 having a uniform porosity. .

As described above, in the present embodiment, the ratio L / R of the length L to the diameter R of the copper fiber 11 is set within a range of 4 or more and 2500 or less. In order to further increase the porosity, the lower limit of the ratio L / R of the length L to the diameter R of the copper fiber 11 is preferably set to 10 or more. In order to reliably obtain the copper porous body 10 having a uniform porosity P, the upper limit L / R of the ratio L / R of the length L to the diameter R of the copper fiber 11 is preferably 500 or less.

In addition, according to the method for producing a copper porous body according to this embodiment, since the oxidation treatment step S21 for oxidizing the copper fibers 11 and the reduction treatment step S22 for reducing the oxidized copper fibers 11 are provided, the copper fibers 11 ( A redox layer is formed on the surface of the skeleton portion 12). Further, by performing the oxidation treatment step S21 and the reduction treatment step S22 in this manner, the porosity normalized conductivity σ _{N can} be 20% IACS or more.

(Second Embodiment)

Next, a copper porous composite member 100 according to a second embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 4 shows a copper porous composite member 100 according to this embodiment. The copper porous composite member 100 includes a copper plate 120 (member 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 of this embodiment is the same as the first embodiment, and a plurality of copper fibers are sintered to form a skeleton portion. Here, the copper fiber is made of copper or a copper alloy, and the ratio of the length L to the diameter R is L / R within a range of 0.02 mm to 1.0 mm in diameter R. It is in the range of 4 or more and 2500 or less. In this embodiment, the copper fiber is made of, for example, C1020 (oxygen-free copper).

In this embodiment, the copper fiber is subjected to shaping such as twisting or bending. Moreover, in the copper porous body 110 of this embodiment, the apparent density ratio D _A is 51% or less of the true density D _T of the 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 portion) and the copper plate 120 constituting the copper porous body 110 as described later. As a result, fine unevenness is generated on the surfaces of the copper fibers (skeleton portion) and the copper plate 120. In this embodiment, the specific surface area of the entire copper porous body 110 is 0.01 m ² / g or more. The specific surface area of the entire copper porous body 110 is preferably 0.03 m ² / g or more, but is not limited thereto.

In the joint portion between the copper fibers constituting the copper porous body 110 and the surface of the copper plate 120, the redox layer formed on the surface of the copper fiber and the redox layer formed on the surface of the copper plate are integrally combined.

In the copper porous body 110 of this embodiment, the porosity P is in the range of 50% to 90%, and the electrical conductivity σ _P of the copper porous body 110 measured by the 4-terminal method is divided by copper. The porosity normalized conductivity σ _N specified by the apparent density ratio D _{A of} the porous body 110 is 20% IACS or more.

The porosity P is preferably within a range of 70% to 90%, but is not limited thereto.

Next, a method of manufacturing the copper porous composite member 100 according to this embodiment will be described with reference to a flowchart in FIG. 5.

First, a copper plate 120 as a component body is prepared (copper plate arrangement step S100). Next, copper fibers are dispersed on the surface of the copper plate 120 to be laminated (copper fiber lamination step S101). Here, in this copper fiber lamination step S101, a plurality of copper fibers are laminated and arranged such that the bulk density D _P is 50% or less of the true density D _T of the copper fibers.

Next, the copper fibers laminated on the surface of the copper plate 120 are sintered to form a copper porous body 110, and the copper porous body 110 and the copper plate 120 are bonded together (sintering step S102 and joining step S103). In the sintering step S102 and the joining step S103, as shown in FIG. 5, it is provided with: an oxidation treatment step S121, which performs the oxidation treatment of the copper fiber and the copper plate 120; and a reduction treatment step S122, which is the oxidation-treated copper The fiber and copper plate 120 are reduced and sintered.

In this embodiment, the copper plate 120 in which copper fibers are laminated is placed in a heating furnace, and the copper fibers are subjected to an oxidation treatment by heating in an oxidizing environment (oxidation treatment step S121). By this oxidation treatment step S121, an oxide layer having a thickness of, for example, 1 μm or more and 100 μm or less is formed on the surfaces of the copper fibers and the copper plate 120.

Here, the conditions of the oxidation treatment step S121 in this embodiment are such that the holding temperature is 500 ° C or higher and 1050 ° C or lower, preferably 600 ° C or higher and 1000 ° C or lower; and the holding time is preferably 5 minutes or longer and 300 minutes or lower. It is in the range of 10 minutes or more and 100 minutes or less.

Next, in this embodiment, after the oxidation treatment step S121 is performed, the copper plate 120 in which copper fibers are laminated and arranged is placed in a firing furnace, and heated in a reducing environment, and the oxidized copper fibers and the copper plate 120 are fed. The reduction treatment is performed to bond the copper fibers to each other and the copper fibers to the copper plate 120 (reduction processing step S122).

Here, the conditions of the reduction processing step S122 in this embodiment are a mixed gas environment of nitrogen and hydrogen, and the maintaining temperature is set to 500 ° C or higher and 1050 ° C, preferably 600 ° C or higher and 1000 ° C or lower. 5 minutes or more and 300 minutes or less, preferably in the range of 10 minutes or more and 100 minutes or less.

With this oxidation treatment step S121 and reduction treatment step S122, a redox layer is formed on the surfaces of the copper fibers (skeleton portion) and the copper plate 120, and fine unevenness is generated.

In addition, an oxide layer is formed on the surfaces of the copper fibers (skeleton portion) and the copper plate 120 by the oxidation treatment step S121, whereby the oxide layer crosslinks the plurality of copper fibers with each other and the copper plate 120. Thereafter, a reduction treatment step S122 is performed to reduce the oxide layers formed on the surfaces of the copper fibers (skeleton portion) and the copper plate 120, and sinter the copper fibers to each other via the redox layer to form a skeleton portion, and to make the copper porous The body 110 is combined with a copper plate 120. The porosity normalized conductivity σ _N of the copper porous body 110 is 20% IACS or more.

According to the manufacturing method described above, the copper porous composite member 100 of this embodiment is produced.

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

Furthermore, in this embodiment, a redox layer is formed on the surfaces of the copper fibers and the copper plate 120 constituting the copper porous body 110, the specific surface area of the entire copper porous body 110 is 0.01 m ² / g or more, and the porosity P Within the range of 50% to 90%, various characteristics such as heat exchange efficiency and water retention can be greatly improved.

In the present embodiment, the redox layer formed on the surface of the copper fiber and the redox layer formed on the surface of the copper plate 120 are formed at the joint portion between the copper fibers constituting the copper porous body 110 and the surface of the copper plate 120. Since the copper porous body 110 and the copper plate 120 are firmly joined together, the strength, electrical conductivity, and thermal conductivity of the joint interface are excellent.

According to the manufacturing method of the copper porous composite member 100 according to this embodiment, the copper fiber is laminated on the surface of the copper plate 120 composed of copper and copper alloy, and the sintering step S102 and the bonding step S103 are simultaneously performed, thereby simplifying the manufacturing process. .

In addition, by performing the oxidation treatment step S121 and the reduction treatment step S122, the porosity normalized conductivity σ _{N can} be 20% IACS or more.

The embodiments of the present invention have been described above, but the present invention is not limited thereto, and can be appropriately modified within a range not departing from the technical idea of the invention.

For example, it has been described that a copper porous body is manufactured using the manufacturing equipment shown in FIG. 3, but it is not limited to this, and other manufacturing equipment may be used to manufacture the copper porous body.

As for the environment of the oxidation treatment steps S21 and S121, as long as it is an oxidation environment in which copper or a copper alloy is oxidized at a predetermined temperature, The gas is not limited to the atmosphere, as long as it is an environment containing 0.5 vol% or more of oxygen in an inert gas (for example, nitrogen). The environment of the reduction processing steps S22 and S122 may be a reducing environment in which copper oxide is reduced to metallic copper or copper oxide is decomposed at a predetermined temperature. Specifically, the environment contains several vol% or more of hydrogen. Nitrogen-hydrogen mixed gas, argon-hydrogen mixed gas, pure hydrogen, or ammonia decomposition gas and propane decomposition gas commonly used in the industry can be applied.

In addition, in this embodiment, it has been described that a skeleton portion of a porous copper body is formed by sintering copper fibers, but the invention is not limited to this, and a porous copper such as a fibrous nonwoven fabric or a metal filter may be prepared. The copper porous body is subjected to oxidation treatment under an oxidizing environment and a holding temperature of 500 ° C to 1050 ° C, and reduction treatment under a reducing environment and a holding temperature of 500 ° C to 1050 ° C. The porosity is normalized, and the electrical conductivity σ _{N is} 20% IACS or more.

Furthermore, in this embodiment, it has been described that a redox layer is formed on the surface of the skeleton portion, but it is not limited to this, and a redox layer may not be formed sufficiently as long as the porosity is normalized and the conductivity σ _N becomes 20 Above% IACS is sufficient.

In this embodiment, the use of copper fibers made of oxygen-free copper (JIS C1020), phosphorous deoxidized copper (JIS C1201, C1220), or refined copper (JIS C1100) has been described, but it is not limited to this. As the material of the copper fiber 11, other highly conductive copper alloys such as Cr copper (C18200) or Cr-Zr copper (C18150) may be used. In this embodiment, copper fiber is used, but copper powder or copper fiber and copper powder may also be used. The last two. The average particle diameter of the copper powder is preferably 0.005 mm or more and 0.3 mm or less, and more preferably 0.01 mm or more and 0.1 mm or less, but is not limited thereto. Moreover, when using both copper fiber and copper powder, it is preferable to contain copper powder with 5% or more and 20% or less with respect to copper fiber, but it is not limited to this.

In the second embodiment, the copper porous composite member having the structure shown in FIG. 4 is taken as an example, but it is not limited to this, and the structure shown in FIGS. 6 to 11 may be used. Copper porous composite member.

Furthermore, in the second embodiment, the preferred method is a method of forming a sintered layer composed of a redox layer at the joint portion of the copper porous body and the member body. However, the method is not limited to this. The welding method (laser welding method, resistance welding method) or a welding method using a solder melted at a low temperature is sufficient as long as the porosity of the copper porous body is normalized and the conductivity σ _{N is} 20% IACS or more.

For example, as shown in FIG. 6, a copper porous composite member 200 having a structure in which a plurality of copper tubes 220 as a member body are inserted into the copper porous body 210 may be used.

Alternatively, as shown in FIG. 7, a copper porous composite member 300 having a structure in which a copper tube 320 bent in a U-shape as a member body is inserted into the copper porous body 310 may be used.

Further, as shown in FIG. 8, a copper porous composite member 400 having a structure in which a copper porous body 410 is bonded to an inner peripheral surface of a copper tube 420 as a member body may be used.

Further, as shown in FIG. 9, a copper porous composite member 500 having a structure in which a copper porous body 510 is bonded to an outer peripheral surface of a copper tube 520 as a member body may be used.

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 an inner peripheral surface and an outer peripheral surface of a copper tube 620 as a member body may be used.

Alternatively, as shown in FIG. 11, a copper porous composite member 700 having a structure in which a copper porous body 710 is bonded to both surfaces of a copper plate 720 as a member body may be used.

[Example]

The results of a confirmation experiment performed to confirm the effect of the present invention will be described below.

(Example 1)

Various porous bodies produced using the materials and production methods shown in Table 1 were prepared. First, the porosity and the porosity normalized conductivity before the heat treatment were measured. Thereafter, the oxidation treatment and the reduction treatment were performed under the conditions described in Table 1, and the porosity and the porosity normalized conductivity after the oxidation treatment and the reduction treatment were measured. The porosity and the normalized porosity 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 a water balance method using a precision balance, and the porosity P was calculated by the following formula. 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 plate-shaped sample cut into a width of 30mm × length of 200mm × thickness of 5mm, in accordance with JIS C2525, Micro-Ohm Hitester3227 manufactured by Hitachi Denki Co., Ltd. was measured at a voltage terminal interval of 150mm and a measurement current of 0.5A by the 4-terminal method Electrical conductivity σ _P (% IACS). Then, the porosity normalized conductivity σ _{N is} calculated according to the following formula.

Porosity normalized conductivity σ _N (% IACS) = σ _P × (1 / D _A )

The apparent density ratio D _A (%) is calculated by the following formula.

Apparent density ratio D _A = 100 × m / (V × D _T )

Here, m: mass of copper porous body (g), V: volume of copper porous body (cm ³ ), D _T : true density of copper or copper alloy constituting copper porous body (g / cm ³ )

In Examples 1-4 of the present invention in which the peroxidation treatment and reduction treatment were performed under the conditions specified in the present invention, the porosity P was all within the range of 50% to 90%, and the porosity was normalized and the conductivity was more than 20%. IACS.

In contrast, in Comparative Example 1 where the temperature condition of the oxidation treatment is low and Comparative Example 2 where the temperature condition of the reduction treatment is low, the conductivity has not been sufficiently improved after the oxidation treatment and the reduction treatment, and the porosity has normalized the conductivity. σ _{N does} not reach 20% IACS.

(Example 2)

The copper powder shown in Table 2 was used for redox treatment under the conditions shown in Table 2 to obtain a copper porous body. Regarding the obtained copper porous body, the porosity and the porosity normalized conductivity were measured. In addition, the porosity and the porosity-normalized conductivity were measured by the same method as in Example 1. In Example 2, the D _T when calculating the porosity-normalized conductivity was calculated using a copper porous structure. The true density (g / cm ³ ) of the copper powder of the mass. The evaluation results are shown in Table 2.

In Examples 11-14 of the present invention in which peroxidation treatment and reduction treatment were performed under the conditions specified in the present invention, the porosity P was all within the range of 50% to 90%, and the porosity was normalized and the conductivity was more than 20%. IACS.

On the other hand, in Comparative Example 11 in which the temperature condition of the oxidation treatment is low and Comparative Example 12 in which the temperature condition of the reduction treatment is low, the porosity normalized conductivity σ _{N does} not reach 20% IACS.

(Example 3)

The copper fibers shown in Table 3 were subjected to redox treatment under the conditions shown in Table 3 to prepare copper porous bodies. The fiber diameter R and the fiber length L of the copper fiber were measured by the following methods.

(Fiber diameter R)

Fiber diameter R (mm) system using using a Malvern particle analyzer manufactured by "Morphologi G3", based on JIS Z 8827-1, an equivalent circular diameter (Heywood diameter) R = (A / π) are calculated by the image analyze ^{1 / 2} x 2 average.

(Fiber length L)

The fiber length L (mm) of the copper fiber is a simple average value calculated from image analysis using a particle analysis device "Morphologi G3" made by Malvern.

Regarding the obtained copper porous body, the porosity and the porosity normalized conductivity were measured. In addition, the porosity and the porosity normalized conductivity were measured by the same method as in Example 1. In Example 3, the D _T when the porosity normalized conductivity was calculated was a copper porous structure. The true density (g / cm ³ ) of plastid copper fibers. The evaluation results are shown in Table 3.

In Examples 21-26 of the present invention in which the peroxidation treatment and reduction treatment were performed under the conditions specified in the present invention, the porosity P was all within the range of 50% to 90%, and the porosity was normalized and the conductivity was more than 20%. IACS.

On the other hand, in Comparative Example 21 where the temperature condition of the oxidation treatment is low and Comparative Example 22 where the temperature condition of the reduction treatment is low, the porosity normalized conductivity σ _{N does} not reach 20% IACS.

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

[Industrial availability]

According to the copper porous body of the present invention, a copper porous composite member obtained by joining the copper porous body to a member body, a method for manufacturing a copper porous body, and a method for manufacturing a copper porous composite member, Copper porosity with sufficient porosity and sufficient electrical and thermal conductivity. The copper porous system is suitable as a conductive member and a heat transfer member.

Claims (11)

A copper porous body is a copper porous body having a skeleton portion of a three-dimensional network structure, and is characterized in that the porosity is within a range of 50% to 90%, and the foregoing is measured by the 4-terminal method. The electrical conductivity of the copper porous body divided by the porosity normalized conductivity σ _N prescribed by the apparent density ratio of the copper porous body is 20% IACS or more. The copper porous body according to claim 1, wherein a redox layer is formed on a surface of the skeleton portion. For example, the copper porous body according to claim 1 or claim 2, wherein the aforementioned skeleton portion is a sintered body of at least one or both of a copper powder and a copper fiber composed of copper or a copper alloy. For example, the copper porous body of claim 3, wherein the copper fiber has a diameter R in a range of 0.02 mm to 1.0 mm, and a ratio L / R of the length L to the diameter R in a range of 4 to 2500. In the copper porous body according to claim 3 or claim 4, wherein at least one of the copper powder and the copper fiber or a combination of both of them is a redox layer formed on the surface of each other, and is integrally combined with each other. A copper porous composite member comprising a member body and a bonded body of the copper porous body according to any one of claims 1 to 5. According to the copper porous composite member of claim 6, wherein a joint surface between the member body and the copper porous body is made of copper or a copper alloy, and a joint portion between the copper porous body and the member body is a sintered layer. A method for manufacturing a copper porous body, which is a method for manufacturing a copper porous body such as the copper porous body of claim 1 or claim 2, characterized in that the skeleton portion of the three-dimensional network structure is Oxidation treatment is performed in an oxidizing environment and maintained at a temperature of 500 ° C to 1050 ° C, and reduction treatment is performed in a reducing environment and a maintenance temperature of 500 ° C to 1050 ° C, so that the porosity normalized conductivity σ _N becomes 20 % IACS or more. A method for producing a copper porous body, which is a method for producing a copper porous body of the copper porous body according to any one of claim 3 to claim 5, characterized in that the copper powder and the foregoing At least one or both of the copper fibers are subjected to an oxidation treatment under an oxidizing environment and a holding temperature of 500 ° C to 1050 ° C, and a reduction treatment under a reducing environment and a holding temperature of 500 ° C to 1050 ° C. The skeleton portion is formed of a sintered body of at least one or both of the copper powder and the copper fiber, and the porosity normalized conductivity σ _{N is} 20% IACS or more. A method for producing a copper porous composite member, which is a method for producing a copper porous composite member composed of a member body and a joint body with the copper porous body according to any one of claims 1 to 5, It is characterized by having a joining step of joining the copper porous body according to any one of claim 1 to claim 5 to the member body. For example, a method for manufacturing a copper porous composite member according to claim 10, The joint surface to be joined to the copper porous body in the member body is made of copper or copper alloy, and the joining step is to join the copper porous body and the member body by sintering.