Porous sintered body and process for producing porous sintered body

Abstract

[Object] The present invention provides a porous sintered body which has a uniform porosity, a high level of freedom in forming, allowing to be formed into varieties of shapes and various levels of porosity, and to be formed to an extremely high level of porosity. [Means for Solution] There is provided a porous sintered body 1 which is obtained by sintering a powder 4 , and includes hollow cores 5 following a vanished shape of an interlaced or otherwise structured fibriform vanisher material 2 ; sintered walls 6 obtained by sintering the powder held around the cores and extending longitudinally of the cores; and voids 7 between the sintered walls.

1 . A porous sintered body obtained by sintering a powder, comprising:
 hollow cores following a vanished shape of an interlaced or otherwise structured fibriform vanisher material;   sintered walls extending longitudinally of the cores and obtained by sintering the powder held around the cores; and   voids between the sintered walls.   
     
     
         2 . The porous sintered body according to  claim 1 , wherein the sintered walls include absent regions which provide communication between the cores and the voids. 
     
     
         3 . The porous sintered body according to  claim 1 , wherein the sintered wall is obtained through necking sintering of the powder which is laminated in one through three layers on outer circumferential regions of the fibriform vanisher material. 
     
     
         4 . The porous sintered body according to  claim 1 , wherein the powder has an average particle size of ⅕ through 1/50 of a diameter of the fibriform vanisher material. 
     
     
         5 . The porous sintered body according to  claim 1 , wherein the powder includes: a first powder which has a higher sintering initiation temperature; and a second powder which has a lower sintering initiation temperature. 
     
     
         6 . The porous sintered body according to  claim 5 , wherein the first powder has a higher sintering initiation temperature than a vanishing completion temperature of the fibriform vanisher material, whereas
 the second powder has a lower sintering initiation temperature than the vanishing completion temperature of the fibriform vanisher material.   
     
     
         7 . The porous sintered body according to  claim 5 , wherein the second powder is sintered to bridge particles of the first powder. 
     
     
         8 . The porous sintered body according to  claim 5 , wherein particles of the first powder are not sintered with each other. 
     
     
         9 . The porous sintered body according to  claim 5 , wherein the second powder has an average particle size not greater than 1/10 of an average particle size of the first powder. 
     
     
         10 . The porous sintered body according to  claim 1 , wherein the porous sintered body is sheet-like and has a thickness of 5 μm through 30 μm. 
     
     
         11 . The porous sintered body according to  claim 1 , wherein the sintered wall has an outer circumference provided with a plated layer. 
     
     
         12 . The porous sintered body according to  claim 1 , wherein the sintered wall has an outer circumference provided with a sintered microparticulate layer. 
     
     
         13 . The porous sintered body according to  claim 1 , obtained by integrally sintering a plurality of porous bodies each provided by an interlaced or otherwise structured fibriform vanisher material having its outer circumferential regions holding a sinterable powder. 
     
     
         14 . A method of making a porous sintered body, comprising:
 a fibriform vanisher material formation step of interlacing or otherwise structuring a fibriform vanisher material into a porous body of a desired shape;   a sintering powder application step of applying a sinterable powder on outer circumferential surfaces of the fibriform vanisher material;   a fibriform vanisher material vanishing step of vanishing the fibriform vanisher material; and   a sintering step of sintering the powder thereby obtaining a porous sintered body which includes: hollow cores resulting from vanishing the fibriform vanisher material; and sintered walls resulting from sintering the powder.   
     
     
         15 . The method of making a porous sintered body according to  claim 14 , wherein
 in the sintering step,   the sinterable powder is sintered and   absent regions are formed in the sintered wall, providing communication between the hollow cores and its outside.   
     
     
         16 . The method of making a porous sintered body according to  claim 14 , wherein the sintering powder is applied in one through three layers on the outer circumferential surfaces of the fibriform vanisher material in the sintering powder application step. 
     
     
         17 . The method of making a porous sintered body according to  claim 14 , wherein mutually adjacent powder particles are necking-sintered in the sintering step. 
     
     
         18 . The method of making a porous sintered body according to  claim 14 , wherein the fibriform vanisher material formation step includes:
 a slurry adjusting step of adjusting a slurry by mixing the fibriform vanisher material, the sinterable powder and a dispersion liquid in which these components can stay in a mixed state in a dispered manner; and   a paper-making step of forming a sheet-body out of the slurry by means of wet papermaking method; whereas   the sintering powder application step includes:   a dehydrating-drying step of dehydrating and/or drying the sheet-like formed-body which contains the slurry, thereby allowing the powder to be held on an outer circumference of the interlaced fibriform vanisher material.   
     
     
         19 . The method of making a porous sintered body according to  claim 14 , wherein the sintering powder application step includes:
 a slurry adjusting step of adjusting a slurry by mixing the sinterable powder with a dispersion liquid in which these components can stay in a mixed state in a dispered manner;   an impregnation step of impregnating the prous body, which has been formed into a desired shape in the fibriform vanisher material formation step, with the slurry in which the sinterable powder is dispersed; and   a dehydrating-drying step of dehydrating and/or drying the formed body which contains the slurry thereby allowing the powder held on an outer circumference of the interlaced fibriform vanisher material.   
     
     
         20 . The method of making a porous sintered body according to  claim 14 , wherein the powder includes a first powder and a second powder each having a different sintering temperature from each other,
 the sintering step including:   a first sintering step of sintering the second powder to bridge particles of the first powder before the first powder begins sintering.   
     
     
         21 . The method of making a porous sintered body according to  claim 20 , wherein the first sintering step is started before the fibriform vanisher material vanishes. 
     
     
         22 . The method of making a porous sintered body according to  claim 20 , further comprising a second sintering step of sintering particles of the first powder with each other after the fibriform vanisher material has varnished. 
     
     
         23 . The method of making a porous sintered body according to  claim 14 , wherein the fibriform vanisher material formation step includes:
 a lamination step of laminating a plurality of fibriform vanisher material of desired shapes; and/or a fibriform vanisher material modification step of working on the fibriform vanisher material.   
     
     
         24 . The method of making a porous sintered body according to  claim 14 , wherein the sintering powder application step includes a plurality of steps for application of different sintering powders.