Method and apparatus for making shaped articles from sprayed molten metal or metal alloy

Abstract

A method and apparatus for manufacturing a shaped precision article from molten metal or molten metal alloy wherein a gas atomized stream of molten metal or molten metal alloy is directed at a collecting surface to form a coherent deposit, the stream being cooled in flight by the atomizing gas, which is at ambient, preferably room temperature, sufficient heat being extracted by the relatively cold atomizing gas from the stream of molten metal in flight such that formation of the coherent deposit is independent or substantially independent of the thermal properties and temperature of the collecting surface, provided the temperature of the collecting surface is below the melting point of the metal or metal alloy being sprayed; and the deposit is worked as by a die to form the precision metal or metal alloy article.

What is claimed and desired to be secured by Letters Patent is: 
     
       1. A method of manufacturing a shaped precision article comprising the steps of directing a stream of molten metal or metal alloy onto a spaced collecting surface having a temperature appreciably less than the melting point of said metal or metal alloy, atomizing said stream by subjecting it to high velocity jets of an inert gas having an initial temperature that is appreciably less than that of said molten metal or metal alloy, said gas temperature being such that sufficient heat is extracted by said gas from said molten metal or metal alloy during flight to said surface that said deposited metal or metal alloy forms a coherent deposit and its formation is independent of the other thermal properties of said surface, and working said deposit by a die to form said article. 
     
     
       2. The method defined in claim 1, wherein said gas is mainly nitrogen at substantially ambient temperature. 
     
     
       3. The method defined in claim 2, wherein said gas is mainly nitrogen at room temperature. 
     
     
       4. The method as defined in claim 1, wherein said deposit is removed from the surface prior to said working. 
     
     
       5. Apparatus for manufacturing a shaped precision article comprising means for directing a stream of molten metal or metal alloy onto a spaced collecting surface having a temperature appreciably less than the melting point of said metal or metal alloy, means for atomizing said stream by subjecting it to high velocity jets of an inert gas having an initial temperature that is appreciably less than that of said molten metal or metal alloy, said gas temperature being such that sufficient heat is extracted by said gas from said molten metal or metal alloy during flight to said surface that said deposit is coherent and its formation independent of the other thermal properties of said surface, and means for working said deposit by a die to form said article. 
     
     
       6. The apparatus defined in claim 5, wherein said gas is mainly or wholly nitrogen at ambient temperature. 
     
     
       7. The apparatus defined in claim 6, wherein said gas is mainly or wholly nitrogen at room temperature. 
     
     
       8. The apparatus defined in claim 5, wherein said metal is steel which, prior to atomising, is at a temperature in the range of 2,500° F.-3,200° F. and said gas is mainly or wholly nitrogen at about 30°-90° F. before atomising and about 900° F. after cooling the metal spray. 
     
     
       9. The apparatus defined in claim 5, wherein said deposit is removed from said surface and said die is distinct from said surface. .Iadd.10. A method of manufacturing from molten metal or metal alloy a deposit which is subsequently worked to form a shaped precision article comprising the steps of directing a stream of molten metal or metal alloy onto a spaced collecting surface having a temperature appreciably less than the melting point of said metal or metal alloy, atomizing said stream into individual particles by subjecting it to high velocity jets of an inert gas having an initial temperature that is appreciably less than that of said molten metal or metal alloy, said gas temperature being such that a sufficient controlled amount of heat is extracted by said gas from said molten metal or metal alloy during flight to said surface, and there being relative movement between said stream and said surface, such that said particles deform and weld together so that the particles lose their individual identities to form a coherent deposit, the solidification of said deposit being independent of the thermal condition and thermal properties of said surface, and working said deposit by a die to form said article..Iaddend. 
     
     
        .Iadd.11.  The method defined in claim 10, wherein the worked deposit is subjected to finish machining and/or heat treatment to form a finished article..Iaddend. .Iadd.12. The method defined in claim 11, wherein said gas is mainly nitrogen at room temperature..Iaddend. .Iadd.13. The method defined in claim 10, wherein said gas is mainly nitrogen at substantially ambient temperature..Iaddend. .Iadd.14. The method defined in claim 10, wherein said deposit is removed from the surface prior to said working..Iaddend. .Iadd.15. Apparatus for manufacturing from molten metal or metal alloy a deposit which is subsequently worked to form a shaped precision article comprising means for directing a stream of molten metal alloy onto a spaced collecting surface having a temperature appreciably less than the melting point of said metal or metal alloy, means for atomizing said stream into individual particles by subjecting it to high velocity jets of an inert gas having an initial temperature that is appreciably less than that of said molten metal or metal alloy, said gas temperature being such that as sufficiently by controlled amount of heat is extracted by said gas from said molten metal or metal alloy during flight to said surface that said particles deform and weld together so that the particles lose their individual identities to form a coherent deposit, the solidification of said deposit being independent of the thermal condition and thermal properties of said surface, and means for working said deposit by a die to form said article..Iaddend. .Iadd.16. The apparatus defined in claim 15, wherein said gas is mainly or wholly 
     
     
        nitrogen at ambient temperature..Iaddend. .Iadd.17.  The apparatus defined in claim 16, wherein said gas is mainly or wholly nitrogen at room temperature..Iaddend. .Iadd.18. The apparatus defined in claim 15, wherein said metal is steel which, prior to atomizing, is at a temperature in the range of 2,500° F.-3,200° F. and said gas is mainly or wholly nitrogen at about 30°-90° F. before atomizing and about 900° F. after cooling the metal spray..Iaddend. .Iadd.19. The apparatus defined in claim 15, wherein said deposit is removed from said surface and said die is distinct from said surface..Iaddend.