Open-porous metal foam body and a method for fabricating the same

Abstract

Disclosed are an open-porous metal foam and a method for manufacturing the same. An open-porous metal foam according to an exemplary embodiment of the present invention is made of an iron-based alloy including 15 wt % or more of chrome and 5 wt % or more of aluminum. The open-porous metal foam is a semi-product that is formed of iron or the iron-based alloy that does not include chrome and aluminum or includes a smaller amount of chrome and aluminum in the powder when manufacturing, and the surface and the open pore thereof are uniformly coated with the powder of the iron-chrome-aluminum alloy and the organic binding agent. When heat treatment is performed under a reduction atmosphere, sintering is performed. In this case, the metal foam body that is formed of the iron-chrome-aluminum alloy is obtained by compensating concentrations of alloy elements between the semi-product and the powder by diffusion, and a content of chrome and aluminum in the metal foam is smaller than a content of chrome and aluminum included in a starting alloy of the used powder.

1 . An open-porous metal foam, comprising:
 an iron-based alloy including 15 wt % or more of chrome(Cr) and 5 wt % or more of aluminum(AI).   
     
     
         2 . The open-porous metal foam of  claim 1 , wherein:
 a web element of the foam is formed in an air-tight manner.   
     
     
         3 . The open-porous metal foam of  claim 2 , wherein:
 the iron-based alloy includes nickel, and a maximum content of nickel is maintained so as to have an alpha (α)-structure in a structure frame.   
     
     
         4 . The open-porous metal foam of  claim 2 , wherein:
 a specific surface area is 10 mm 2 /mm 3  to 25 mm 2 /mm 3 , and surface roughness of the web factor facing an open pore is 50 μm to 200 μm.   
     
     
         5 . The open-porous metal foam of  claim 2 , wherein:
 at least one alloying element selected from yttrium (Y), hafnium (Hf), manganese (Mn), silicon (Si) and zirconium (Zr) is included in an amount of greater than 0 wt % to less than 1 wt %.   
     
     
         6 . The open-porous metal foam of  claim 1 , wherein:
 the iron-based alloy includes nickel, and a maximum content of nickel is maintained so as to have an alpha (α)-structure in a structure frame.   
     
     
         7 . The open-porous metal foam of  claim 6 , wherein:
 a specific surface area is 10 mm 2 /mm 3  to 25 mm 2 /mm 3 , and surface roughness of the web element facing an open pore is 50 μm to 200 μm.   
     
     
         8 . The open-porous metal foam of  claim 7 , wherein:
 at least one alloying element selected from yttrium (Y), hafnium (Hf), manganese (Mn), silicon (Si) and zirconium (Zr) is included in an amount of greater than 0 wt % to less than 1 wt %.   
     
     
         9 . The open-porous metal foam of  claim 6 , wherein:
 at least one alloying element selected from yttrium (Y), hafnium (Hf), manganese (Mn), silicon (Si) and zirconium (Zr) is included in an amount of greater than 0 wt % to less than 1 wt %.   
     
     
         10 . The open-porous metal foam of  claim 1 , wherein:
 a specific surface area is 10 mm 2 /mm 3  to 25 mm 2 /mm 3 , and surface roughness of the web factor facing an open pore is 50 μm to 200 μm.   
     
     
         11 . The open-porous metal foam of  claim 10 , wherein:
 at least one alloying element selected from yttrium (Y), hafnium (Hf), manganese (Mn), silicon (Si) and zirconium (Zr) is included in an amount of more than 0 wt % to less than 1 wt %.   
     
     
         12 . The open-porous metal foam of  claim 1 , wherein:
 at least one alloying element selected from yttrium (Y), hafnium (Hf), manganese (Mn), silicon (Si) and zirconium (Zr) is included in an amount of greater than 0 wt % to less than 1 wt %.   
     
     
         13 . A method for manufacturing an open-porous metal foam, comprising:
 providing a semi-product that does not include chrome and aluminum or include a smaller amount than an amount in powder of an iron-chrome-aluminum alloy and is formed of iron or an iron-based alloy;   uniformly coating a surface and an opened pore of the semi-product that is formed of the iron or the iron-based alloy with the powder of the iron-chrome-aluminum alloy and an organic binding agent;   discharging organic components by heat treating the semi-product that is formed of the coated iron or iron-based alloy under a reducing atmosphere at a temperature of 300 to 600° C.; and   sintering the semi-product that is formed of the iron or the iron-based alloy from which the organic components are discharged at the temperature of 900° C. or more.   
     
     
         14 . The method of  claim 13 , wherein:
 the semi-product uses a foam in which the iron or the iron-based alloy is deposited on the organic open-porous foam by an electroplating manner.   
     
     
         15 . The method of  claim 14 , wherein:
 an average particle size of the powder is 20 μm to 50 μm.   
     
     
         16 . The method of  claim 14 , wherein:
 the sintering is heated at a heating speed of 5 K/min to 1300° C., and the temperature is maintained for at least 30 min.   
     
     
         17 . The method of  claim 13 , wherein:
 an average particle size of the powder is 20 μm to 50 μm.   
     
     
         18 . The method of  claim 13 , wherein:
 when the sintering is performed, the metal foam that is formed of the iron-chrome-aluminum alloy is formed by compensating concentrations of alloy elements between the semi-product and the powder by diffusion, and a content of chrome and aluminum in the metal foam is smaller than a content of chrome and aluminum included in a starting alloy of the used powder.   
     
     
         19 . The method of  claim 18 , wherein:
 the sintering is heated at a heating speed of 5 K/min to 1300° C., and the temperature is maintained for at least 30 min.   
     
     
         20 . The method of  claim 13 , wherein:
 the sintering is heated at a heating speed of 5 K/min to 1300° C., and the temperature is maintained for at least 30 min.