Porous copper body, porous copper composite member, method for producing porous copper body, and method for producing porous copper composite member

Abstract

The porous copper body of the disclosure includes a skeleton having a three-dimensional network structure, in which a porosity is in a range of 50% to 90% and a porosity-normalized electrical conductivity σ N which is defined by dividing a electrical conductivity of the porous copper body, measured by a 4-terminal sensing, by an apparent density ratio of the porous copper body is 20% IACS or higher.

1 . A porous copper body, comprising: a skeleton having a three-dimensional network structure,
 wherein a porosity is in a range of 50% to 90%, and   a porosity-normalized electrical conductivity σ N  which is defined by dividing a electrical conductivity of the porous copper body, measured by a 4-terminal sensing, by an apparent density ratio of the porous copper body is 20% IACS or higher.   
     
     
         2 . The porous copper body according to  claim 1 , wherein an oxidation-reduction layer is formed on a surface of the skeleton. 
     
     
         3 . The porous copper body according to  claim 1 , wherein the skeleton is a sintered body of: at least one of copper powders and copper fibers; or both of copper powders and copper fibers, both of copper powders and copper fibers being made of copper or a copper alloy. 
     
     
         4 . The porous copper body according to  claim 3 , wherein each of the copper fibers has a diameter R in a range of 0.02 mm to 1.0 mm, and a ratio L/R between a length L and the diameter R in a range of 4 to 2500. 
     
     
         5 . The porous copper body according to  claim 3 , wherein, in a bonding portion of: at least one of copper powders and copper fibers; or both of copper powders and copper fibers, the oxidation-reduction layers formed on surfaces of: at least one of copper powders and copper fibers; or both of copper powders and copper fibers, are integrally bonded to each other. 
     
     
         6 . A porous copper composite member, comprising a bonded body of a main member body and the porous copper body according to  claim 1 . 
     
     
         7 . The porous copper composite member according to  claim 6 ,
 wherein in the main member body, a bonding surface with the porous copper body is formed from copper or a copper alloy, and   a bonding portion of the porous copper body and the main member body is a sintered layer.   
     
     
         8 . A method of manufacturing the porous copper body according to  claim 1 , the method comprising:
 performing an oxidation treatment on a skeleton having a three-dimensional network structure under conditions of a holding temperature of 500° C. to 1050° C. in an oxidizing atmosphere; and   performing a reduction treatment on the skeleton having a three-dimensional network structure under conditions of a holding temperature of 500° C. to 1050° C. in a reducing atmosphere,   wherein the porosity-normalized electrical conductivity σ N  is set to 20% IACS or higher by the oxidation treatment and the reduction treatment.   
     
     
         9 . A method of manufacturing the porous copper body according to  claim 3 , the method comprising:
 performing an oxidation treatment on at least one of copper powders and copper fibers, or both of copper powders and copper fibers, under conditions of a holding temperature of 500° C. to 1050° C. in an oxidizing atmosphere; and   performing a reduction treatment on at least one of copper powders and copper fibers, or both of copper powders and copper fibers, under conditions of a holding temperature of 500° C. to 1050° C. in a reducing atmosphere,   wherein, by the oxidation treatment and the reduction treatment, the skeleton including a sintered body of: at least one of copper powders and copper fibers; or both of copper powders and copper fibers, are formed and the porosity-normalized electrical conductivity σ N  is set to 20% IACS or higher.   
     
     
         10 . A method of manufacturing a porous copper composite member including a bonded body of a main member body and a porous copper body, the method comprising a bonding process of bonding the porous copper body according to  claim 1  and the main member body to each other. 
     
     
         11 . The method of manufacturing a porous copper composite member according to  claim 10 ,
 wherein in the main member body, a bonding surface to which the porous copper body is bonded is constituted by copper or a copper alloy, and   in the bonding process, the porous copper body and the main member body are bonded to each other through sintering.   
     
     
         12 . The porous copper body according to  claim 2 , wherein the skeleton is a sintered body of: at least one of copper powders and copper fibers; or both of copper powders and copper fibers, both of copper powders and copper fibers being made of copper or a copper alloy. 
     
     
         13 . The porous copper body according to  claim 12 , wherein each of the copper fibers has a diameter R in a range of 0.02 mm to 1.0 mm, and a ratio L/R between a length L and the diameter R in a range of 4 to 2500. 
     
     
         14 . The porous copper body according to  claim 4 , wherein, in a bonding portion of: at least one of copper powders and copper fibers; or both of copper powders and copper fibers, the oxidation-reduction layers formed on surfaces of: at least one of copper powders and copper fibers; or both of copper powders and copper fibers, are integrally bonded to each other. 
     
     
         15 . The porous copper body according to  claim 12 , wherein, in a bonding portion of: at least one of copper powders and copper fibers; or both of copper powders and copper fibers, the oxidation-reduction layers formed on surfaces of: at least one of copper powders and copper fibers; or both of copper powders and copper fibers, are integrally bonded to each other. 
     
     
         16 . The porous copper body according to  claim 13 , wherein, in a bonding portion of: at least one of copper powders and copper fibers; or both of copper powders and copper fibers, the oxidation-reduction layers formed on surfaces of: at least one of copper powders and copper fibers; or both of copper powders and copper fibers, are integrally bonded to each other. 
     
     
         17 . A method of manufacturing the porous copper body according to  claim 2 , the method comprising:
 performing an oxidation treatment on a skeleton having a three-dimensional network structure under conditions of a holding temperature of 500° C. to 1050° C. in an oxidizing atmosphere; and   performing a reduction treatment on the skeleton having a three-dimensional network structure under conditions of a holding temperature of 500° C. to 1050° C. in a reducing atmosphere,   wherein the porosity-normalized electrical conductivity σ N  is set to 20% IACS or higher by the oxidation treatment and the reduction treatment.   
     
     
         18 . A method of manufacturing the porous copper body according to  claim 12 , the method comprising:
 performing an oxidation treatment on at least one of copper powders and copper fibers, or both of copper powders and copper fibers, under conditions of a holding temperature of 500° C. to 1050° C. in an oxidizing atmosphere; and   performing a reduction treatment on at least one of copper powders and copper fibers, or both of copper powders and copper fibers, under conditions of a holding temperature of 500° C. to 1050° C. in a reducing atmosphere,   wherein, by the oxidation treatment and the reduction treatment, the skeleton including a sintered body of; at least one of copper powders and copper fibers; or both of copper powders and copper fibers, are formed and the porosity-normalized electrical conductivity σ N  is set to 20% IACS or higher.