Infiltrated ferrous materials

Abstract

Metallic alloys and methods for the preparation of free-standing metallic materials in a layerwise manner. The resulting layerwise construction provides a metallic skeleton of selected porosity which may be infiltrated with a second metal to provide a free-standing material that has a volume loss of less than or equal to 130 mm3 as measured according to ASTM G65-04(2010).

What is claimed is: 
     
         1 . A method for layer-by-layer formation of a free-standing metallic part comprising:
 supplying metallic alloy particles comprising, in weight percent:
 17.0<Cr<22.0; 
 8.0<Mo<12.0; 
 2.0<B<5.0; 
 3.0<W<7.0; 
 0.5<C<2.0; 
 1.0<Mn<4.0; 
 1.0<Si<3.0; and 
 balance Fe; 
   mixing the metallic alloy particles with a binder wherein the binder bonds the powder particles and forming a layer of the free-standing metallic part wherein the layer has a porosity of in the range of 20% - 60%;   heating the metallic alloy powder and the binder and forming a bond between the particle;   sintering the metallic alloy powder and the binder by heating and removing the binder and cooling and forming a porous metallic skeleton; and   infiltrating the porous metallic skeleton with a second material and forming the free-standing metallic part wherein the part has a volume loss of less than or equal to 130 mm3 as measured according to ASTM G65-04(2010).