Component produced or processed by powder metallurgy, and process for producing

Abstract

The invention relates to components which are produced or processed by powder metallurgy, and to processes for producing components of this type. The components produced by powder metallurgy are intended both to have porous regions and to provide fluid-light properties, and it should also be possible to produce them at correspondingly low cost and suitably flexibly. For this purpose, a component of this type has at least one porous region, which is formed from an intermetallic phase or solid solutions. However, it may also have a corresponding surface coating. Moreover, in a component of this type there is at least one areal fluid-tight region which is formed from a metal or metal alloy of the corresponding intermetallic phase or solid solution.

1 . A component which is produced or processed by powder metallurgy and has at least one porous region, which is formed from an intermetallic phase or solid solutions or has a surface coating of this type, and at least one areal fluid-tight region, which is formed from a metal, a metal alloy, and the corresponding intermatallic phase or solid solution.  
     
     
         2 . The component as claimed in  claim 1 , wherein the fluid-tight region forms part of the outer shell of the component.  
     
     
         3 . The component as claimed in  claim 1 , wherein the fluid-tight region is surrounded by the porous region.  
     
     
         4 . The component as claimed in,  claim 1  wherein the corresponding intermetallic phase or the solid solutions are selected from at least one of the four consisting of nickel, aluminum, molybdenum, tungsten, iron, titanium, cobalt, copper, silicon, cerium, tantalum, niobium, tin, zinc and bismuth.  
     
     
         5 . The component as claimed in,  claim 1  wherein at least the porous region is formed from nickel aluminide or is coated therewith.  
     
     
         6 . The component as claimed in,  claim 1  wherein at least the porous region has a porosity and density which change in steps or gradually in the direction of the areal fluid-tight region.  
     
     
         7 . The component as claimed in,  claim 1  wherein at least the porous region is formed from a metal or metal alloy of the corresponding intermetallic phase or solid solution.  
     
     
         8 . The component as claimed in,  claim 1  wherein at least one passage or aperture is formed in the areal fluid-tight region.  
     
     
         9 . The component as claimed in,  claim 1  wherein the areal, fluid-tight region has a density of over 96% of the theoretical density.  
     
     
         10 . A process for producing a component which is produced or processed by powder metallurgy and has at least one porous region, which is formed from an intermetallic phase or solid solutions or has a surface coating of this type, and at least one areal fluid-tight region, which is formed from a metal, a metal alloy, and the corresponding intermetallic phase or solid solution wherein a starting powder which has a sintering activity and forms intermetallic phases or solid solutions is used to form the areal fluid-tight region.  
     
     
         11 . The process as claimed in  claim 10  wherein a starting powder with a grain size d 50 <50 μm and a powder with a sintering activity obtained by high-energy milling are used for production.  
     
     
         12 . The process as claimed in  claim 11  wherein a powder perform is produced from differentiated starting powders, the dimensions of which perform take account of the different shrinkages of the differentiated starting powders during sintering.  
     
     
         13 . A process for producing a component which is produced or processed by powder metallurgy and has at least one porous region, which is formed from an intermetallic phase or solid solutions or has a surface coating of this type, and at least one areal fluid-tight region, which is formed from a metal, a metal alloy, and the corresponding intermetallic phase or solid solution wherein a porous structure, which forms the porous region, is coated with a powder which has a sintering activity and forms intermetallic phases or solid solutions, and the areal fluid-tight region is formed at a surface of the component by a subsequent sintering operation.  
     
     
         14 . A process for producing a component which is produced or processed by powder metallurgy and has at least one porous region, which is formed from an intermetallic phase or solid solutions or has a surface coating of this type, and at least one areal fluid-tight region, which is formed from a metal, a metal alloy, and the corresponding intermetallic phase or solid solution wherein a metallic, areal and fluid-tight element, which forms the fluid-tight region, is coated with a layer of a powder which contains at least one element of the intermetallic phase or solid solution, and the fluid-tight region is joined to a porous structure, which has been placed on top of the powder layer and forms the porous region, by sintering.