초록 ▼

A method of making a porous metal article is disclosed comprising: (a) applying a stabilized suspension of a dispersed metal particulate in a fluid medium to a porous metal support; (b) working the support to fill the openings with the stabilized suspension and remove entrained gas; (c) heating

A method of making a porous metal article is disclosed comprising: (a) applying a stabilized suspension of a dispersed metal particulate in a fluid medium to a porous metal support; (b) working the support to fill the openings with the stabilized suspension and remove entrained gas; (c) heating the filled support to dry the stabilized suspension and provide the filled support with green or unsintered strength; (d) preferably compressing the dried, filled support to provide better contact between adjacent particles and greater mechanical strength; and (e) sintering the compressed, dried, filled support to remove volatile material and to fuse the individual particles of the metal particulate to the metal support and to each other. The porous metal articles find particular use as filters. They comprise a porous metal support and metal particulate material with the individual particles sinter bonded to each other and to the support. Preferably, the porous articles are formed from austenitic stainless steel containing less than 0.03 parts by weight carbon, have F2 pore ratings at beta=100 of from about 0.1 to about 50 micrometers and are capable of being formed about a bending radius of five or less times the thickness of the article while maintaining their integrity.

대표청구항 ▼

1. A method of making a porous metal filter medium comprising: (a) applying a stabilized or thixotropic suspension of a metal particulate dispersed in a fluid medium containing a stabilizing agent and a binding agent to a foraminate metal support, said suspension having a viscosity in the range o

1. A method of making a porous metal filter medium comprising: (a) applying a stabilized or thixotropic suspension of a metal particulate dispersed in a fluid medium containing a stabilizing agent and a binding agent to a foraminate metal support, said suspension having a viscosity in the range of from about 200 to about 50,000 centipoise; (b) working said support to fill the openings thereof with said suspension and to remove entrained gas; (c) removing any excess of said suspension from said support; (d) heating the filled support to dry said suspension and provide the filled support with green or unsintered strength, the drying of said suspension being carried out without contacting the filled support of step (c) with any surface until said filled support has been dried; (e) compressing the dried, filled support to provide better contact between adjacent particles and greater mechanical strength; and (f) sintering the compressed, dried, filled support to remove volatile material and fuse the individual particles of said metal particulate to each other and to said support; wherein the individual particles of said metal particulate are no more than one-fifth the size of the openings of said foraminate metal support whereby a porous metal filter medium is provided capable of being formed about a bending radius five times the thickness of said medium. 2. The method of claim 1 wherein said working of said support is carried out by carrying said support through a bath of said stabilized suspension over rolls contacting opposite sides of said support to extrude said stabilized suspension through said support first in one direction and then the other. 3. The method of claim 1 wherein, prior to said heating, the filled support is passed through spaced doctor blades to remove any excess of said stabilized suspension and to define the thickness of said stabilized suspension. 4. The method of claim 3 wherein said compressing of said dried, filled support is carried out by passing said dried, filled support through spaced calendering rolls. 5. The method of claim 4 wherein said compressing is carried out with a reduction in thickness of said dried, filled support not exceeding 60 percent. 6. The method of claim 4 wherein, after said sintering of said compressed, dried, filled support, the resulting sintered porous metal filter medium is further compressed. 7. The method of claim 4 wherein said support is stainless steel and said metal particulate is stainless steel powder. 8. The method of claim 7 wheren said sintering is carried out at a temperature in the range of from about 1,600 to about 2,500 degrees F. 9. The method of claim 8 wherein said sintering is carried out in a reducing atmosphere or in vacuum at a temperature in the range of from about 1,900 to about 2,375 degrees F. 10. A method of making a porous metal filter medium comprising: (a) applying a stabilized or thixotropic suspension of a stainless steel powder dispersed in a fluid medium containing a stabilizing agent and a binding agent to a stainless steel wire mesh screen, said suspension having a viscosity in the range of from about 200 to about 50,000 centipoise; (b) working said screen to fill the mesh openings thereof with said suspension and to remove entrained gas; (c) heating the filled screen to dry said stabilized suspension and provide said filled screen with green or unsintered strength; (d) compressing the dried, filled screen to provide better contact between adjacent particles and greater mechanical strength; and (e) sintering the compressed, dried, filled screen in a reducing atmosphere or in vacuum at a temperature in the range of from about 1,900 to about 2,375 degrees F. to remove volatile material and bond the individual particles of said stainless steel powder to each other and to said stainless steel screen; wherein the individual particles of said stainless steel powder are no more than one-fifth the size of the openings of said stainless steel screen whereby a porous metal filter medium is provided capable of being formed about a bending radius five times the thickness of said medium. 11. A method of making a porous metal filter medium comprising: (a) applying a stabilized or thixotropic suspension of a metal particulate dispersed in a fluid medium containing a stabilizing agent and a binding agent to a foraminate metal support, said suspension having a viscosity in the range of from about 200 to about 50,000 centipoise; (b) working said support to fill the openings of said support with said suspension and to remove entrained gas; (c) heating the filled support to dry said suspension and provide said filled support with green or unsintered strength; and (d) sintering the dried, filled support without contact with ceramic particulate material; wherein the individual particles of said metal particulate are no more than one-fifth the size of the openings of said foraminate metal support whereby a porous metal filter medium is provided which is capable of being formed about a bending radius five times the thickness of said medium. 12. The method of claim 11 wherein said working of said support is carried out by carrying said support through a bath of said suspension over rolls contacting opposite sides of said support to extrude said suspension through said support first in one direction and then the other. 13. The method of claim 11 wherein, prior to said heating, the filled support is passed through spaced doctor blades to remove any excess of said suspension and to define the thickness of said suspension. 14. The method of claim 13 wherein the sintered support is compressed. 15. The method of claim 14 wherein the compression of said sintered support is carried out by passing said sintered support through spaced calendering rolls. 16. The method of claim 15 wherein said compression is carried out with a reduction in thickness of said sintered support not exceeding 60 percent. 17. The method of claim 16 wherein after said compression, the compressed sintered support is resintered and recompressed. 18. The method of claim 14 wherein said foraminate metal support is stainless steel and said metal particulate is stainless steel powder. 19. The method of claim 18 wherein said sintering is carried out at a temperature in the range of from about 1,600 to about 2,500 degrees F. 20. The method of claim 19 wherein said sintering is carried out in a reducing atmosphere or in vaccum at a temperature in the range of from about 1,900 to about 2,375 degrees F. 21. A method of making a porous metal filter medium comprising: (a) applying a stabilized or thixotropic suspension of a stainless steel powder dispersed in a fluid medium containing a stabilizing agent and a binding agent to a stainless steel wire mesh screen, said suspension having a viscosity in the range of from about 200 to about 50,000 centipoise; (b) working said screen to fill the mesh openings of said screen with said suspension and remove entrained gas; (c) heating the filled screen to dry said suspension and provide said filled screen with green or unsintered strength; (d) sintering the dried, filled screen in a reducing atmosphere or in vacuum at a temperature in the range of from about 1,900 to about 2,375 degrees F. without the use of a support or substrate to maintain the particulate material in position on the screen to remove volatile material and bond the individual particles of said stainless steel powder to said stainless steel screen and to each other; wherein the individual particles of said stainless steel powder are no more than one-fifth the size of the openings of said stainless steel screen whereby a porous metal filter medium is provided capable of being formed about a bending radius five times the thickness of said medium.