Chemical vapor deposition and powder formation using thermal spray

Abstract

A method for chemical vapor deposition using a very fine atomization or vaporization of a reagent containing liquid or liquid-like fluid near its supercritical temperature, where the resulting atomized or vaporized solution is entered into a flame or a plasma torch, and a powder is formed or a coating is deposited onto a substrate. The combustion flame can be stable from 10 torr to multiple atmospheres, and provides the energetic environment in which the reagent contained within the fluid can be reacted to form the desired powder or coating material on a substrate. The plasma torch likewise produces the required energy environment, but, unlike the flame, no oxidizer is needed so materials stable in only very low oxygen partial pressures can be formed. Using either the plasma torch or the combustion plasma, coatings can be deposited and powders formed in the open atmosphere without the necessity of a reaction chamber, but a chamber may be used for various reasons including process separation from the environment and pressure regulation.

1 ) A chemical process in which a reactable spray composed of droplets predominantly less than 10 microns in size are reacted in a reaction process to form carbonaceous material.  
     
     
         2 ) The process of  claim 1  wherein the droplets are predominantly less than 2 microns in diameter.  
     
     
         3 ) The process of  claim 1  wherein the reaction process is a combustion reaction.  
     
     
         4 ) The process of  claim 1  wherein the reactable spray contains a cation precursor.  
     
     
         5 ) The process of  claim 4  wherein the material formed is an inorganic and carbonaceous material composite.  
     
     
         6 ) The process of  claim 1  in which a liquid source for the droplets contains liquefied or dissolved gas.  
     
     
         7 ) The process of  claim 1  in which a liquid source of the said droplets is heated sufficiently and released through a nozzle to yield the desired formed size and distribution of carbonaceous material.  
     
     
         8 ) The process of  claim 1  in which the composite material formed is a powder.  
     
     
         9 ) The process of  claim 1  in which the composite material formed is a coating or layer.  
     
     
         10 ) The process of  claim 1  in which the material is formed at or above ambient pressure.  
     
     
         11 ) The process of  claim 1  in which the material is formed in vacuum.  
     
     
         12 ) The process of  claim 1  in which at least one additional material is formed and becomes apart a composite with the carbonaceous material.  
     
     
         13 ) The process of  claim 1  in which the material formed is an inorganic material.  
     
     
         14 ) The process of  claim 1  in which the spray is a combustable spray and the reaction occurs due to a flame.  
     
     
         15 ) The process of  claim 14  in which the spray velocity is greater than the flame speed and there is an ignition source to support the combustion.  
     
     
         16 ) A nanophase composite, said composite comprising inorganic material in part with a carbonaceous material.  
     
     
         17 ) The composite of  claim 16  in which the composite is a powder with a particle size of less than 1 micron.  
     
     
         18 ) The composite of  claim 16  in which the composite is a powder with particle size of less than 100 nm.  
     
     
         19 ) The composite of  claim 16  in which the composite is a layer or coating.  
     
     
         20 ) The composite of  claim 16  in which the composite is a powder with additional material bonded to the surface of the carbonaceous material.  
     
     
         21 ) The composite of  claim 20  in which the thus formed material is electrochemically active.  
     
     
         22 ) The composite of  claim 16  in which the inorganic material is a metal.  
     
     
         23 ) The composite of  claim 16  in which the formed material adds electrical conductivity to a medium when the medium and the composite are combined.