Particulates for additive manufacturing techniques

Abstract

A particulate for an additive manufacturing technique includes metallic particulate bodies with exterior surfaces bearing a polymeric coating. The polymeric coating is conformally disposed over the exterior surface that prevents the underlying metallic body from oxidation upon exposure to the ambient environment by isolating the metallic particulate bodies from the ambient environment. Feedstock materials for additive manufacturing techniques, and methods of making such feedstock, are also disclosed.

1 . A particulate for an additive manufacturing technique, particles of the particulate comprising:
 a particulate body having a surface; and   a polymeric coating disposed over the surface of the particulate body, wherein the particulate body includes a metallic material prone to oxidation upon exposure to the ambient environment, wherein the polymeric coating forms a barrier isolating the particulate body from the ambient environment.   
     
     
         2 . The particulate as recited in  claim 1 , wherein the particulate body includes only elemental copper. 
     
     
         3 . The particulate as recited in  claim 1 , wherein the coating includes polydimethylsiloxane. 
     
     
         4 . The particulate as recited in  claim 1 , wherein the particulate body is oxide-free. 
     
     
         5 . The particulate as recited in  claim 1 , wherein an interface between the particulate body and the polymeric coating is metallic oxide-free. 
     
     
         6 . A particulate feedstock for an additive manufacturing technique including particulate as recited in  claim 1 , wherein the feedstock has greater flowability than uncoated copper particulate. 
     
     
         7 . The particulate feedstock for an additive manufacturing technique including particulate as recited in  claim 1 , wherein the particulate is brighter than uncoated copper particulate. 
     
     
         8 . A conductor formed from particulate as recited in  claim 1 , wherein the conductor has porosity that is less than a porosity of a conductor formed from particulate composite of elemental copper and copper oxide. 
     
     
         9 . A method of making particulate for an additive manufacturing technique, the method comprising:
 receiving a metallic particulate at a fluidized bed apparatus;   flowing a reducing gas through the metallic particulate;   flowing a drying and degassing gas through the metallic particulate; and   flowing a coating gas from vessel containing a polymeric material maintained at a polymeric material vaporization temperature through the metallic particulate,   wherein the metallic particulate is maintained at a coating temperature that is less than the polymeric material vaporization temperature to encapsulate the metallic particulate with polymeric material coatings, particles of the particulate having:
 a particulate body having a surface; and 
 a polymeric coating disposed over the surface of the particulate body, wherein the particulate body includes a metallic material prone to oxidation upon exposure to the ambient environment, wherein the polymeric coating forms a barrier isolating the particulate body from the ambient environment. 
   
     
     
         10 . The method as recited in  claim 9 , wherein the metallic particulate is maintained at a drying and degassing temperature while the drying and degassing gas is flowed therethrough at a temperature that is lower than a reducing temperature at which the metallic particulate is held while the reducing gas is flowed therethrough. 
     
     
         11 . The method as recited in  claim 9 , wherein the metallic particulate is maintained at coating temperature while the coating gas is flowed therethrough that is less than a drying and degassing temperature at which the metallic particulate is held while the drying the degassing temperature is flowed therethrough. 
     
     
         12 . The method as recited in  claim 9 , wherein the coating gas is flowed from a vessel containing polymeric material that is maintained at a polymeric material vaporization temperature that is greater than a coating temperature at which the metallic particulate is maintained while the coating gas is flowed therethrough. 
     
     
         13 . The method as recited in  claim 9 , wherein flowing a reducing gas through the metallic particulate includes removing substantially all oxygen from oxidized portions of the metallic particulate prior to flowing the coating gas through the particulate material. 
     
     
         14 . The method as recited in  claim 9 , wherein flowing a degassing and drying gas flow through the metallic particulate includes removing water vapor generated during the reducing process from the metallic particulate. 
     
     
         15 . The method as recited in  claim 9 , wherein flowing a drying and degassing gas through the metallic particulate and flowing the coating gas through the metallic particulate include flowing an inert gas from a common inert gas source. 
     
     
         16 . The particulate as recited in  claim 1 , wherein the polymeric coating encapsulates the particulate body. 
     
     
         17 . The particulate as recited in  claim 1 , wherein the polymeric coating encapsulates the entirety of the surface of the particulate body. 
     
     
         18 . The particulate as recited in  claim 1 , wherein the polymeric coating is condensed over the surface of the particulate body. 
     
     
         19 . The particulate as recited in  claim 1 , wherein the polymeric coating is condensed over the entirety of the surface of the particulate body. 
     
     
         20 . An additive manufacturing technique, comprising:
 receiving a metallic particulate at a fluidized bed apparatus;   flowing a reducing gas through the metallic particulate;   flowing a drying and degassing gas through the metallic particulate; and   flowing a coating gas from vessel containing a polymeric material maintained at a polymeric material vaporization temperature through the metallic particulate,   wherein the metallic particulate is maintained at a coating temperature that is less than the polymeric material vaporization temperature to encapsulate the metallic particulate with polymeric material coatings, particles of the particulate having:
 a particulate body having a surface; and 
 a polymeric coating disposed over the surface of the particulate body, wherein the particulate body includes a metallic material prone to oxidation upon exposure to the ambient environment, wherein the polymeric coating forms a barrier isolating the particulate body from the ambient environment; and 
   forming a conductor from the coated particulate using an additive manufacturing technique, the conductor having porosity that is less than a porosity of a conductor formed from particulate composite of elemental copper and copper oxide.