Solid-free-form fabrication of hot gas valves

Abstract

The present invention provides methods of manufacturing a hot gas valve for a divert and attitude control system in a propelled craft. The methods include the steps of building a valve, or a plurality of separate valve components or segments using a solid free-form fabrication process, and assembling the plurality of separate valve components or segments if necessary to produce the hot gas valve. The solid free-form fabrication process comprises the steps of forming successive feedstock layers by depositing the feedstock material into a predetermined region, the feedstock layers representing successive cross-sectional component slices, and modifying the feedstock by directing an energy source to the predetermined region and thereby creating modified regions in the successive feedstock layers, the combined modified regions defining the hot gas valve or an at least partially-formed valve component or segment.

1 . A method of manufacturing a hot gas valve for a divert and attitude control system in a propelled craft, the method comprising: 
 building a plurality of separate valve components using a solid free-form fabrication process comprising the steps of: 
 forming successive feedstock layers by depositing the feedstock material into a predetermined region, the feedstock layers representing successive cross-sectional component slices, and  
 modifying the feedstock by directing an energy source to the predetermined region and thereby creating modified regions in the successive feedstock layers, the combined modified regions defining an at least partially-formed valve component; and  
   assembling the plurality of separate valve components to produce the hot gas valve.    
   
   
       2 . The method of  claim 1 , further comprising: 
 machining at least one of the at least partially-formed valve components prior to assembling the plurality of separate valve components to produce the hot gas valve.    
   
   
       3 . The method of  claim 2 , wherein machining is a process selected from the group consisting of electro-discharge machining and grinding.  
   
   
       4 . The method of  claim 1 , further comprising: 
 machining the hot gas valve after assembling the plurality of separate valve components to bring the hot gas valve to final dimensions.    
   
   
       5 . The method of  claim 4 , wherein machining is a process selected from the group consisting of electro-discharge machining and grinding.  
   
   
       6 . The method of  claim 1 , wherein the valve components built using a solid free-form fabrication process include at least one component selected from the group consisting of first and second side thrusters, a disc chamber, a disc, and a fluidic amplifier module.  
   
   
       7 . The method of  claim 6 , wherein the valve components built using a solid free-form fabrication process include the fluidic amplifier module.  
   
   
       8 . The method of  claim 1 , wherein assembling the plurality of separate valve components comprises diffusion bonding the components together to produce the hot gas valve.  
   
   
       9 . The method of  claim 1 , wherein the solid free-form fabrication process is an ion fusion formation process.  
   
   
       10 . A solid free-form fabrication method of manufacturing a hot gas valve for a divert and attitude control system in a propelled craft, the method comprising: 
 forming successive feedstock layers by depositing the feedstock material into a predetermined region, the feedstock layers representing successive cross-sectional slices of the hot gas valve; and    modifying the feedstock by directing an energy source to the predetermined region and thereby creating modified regions in the successive feedstock layers, the combined modified regions defining at least a segment of a hot gas valve in net or near-net shape.    
   
   
       11 . The method of  claim 10 , wherein the combined modified regions define a completed hot gas valve in net or near-net shape.  
   
   
       12 . The method of  claim 11 , further comprising: 
 machining the completed hot gas valve to bring the completed hot gas valve to final dimensions.    
   
   
       13 . The method of  claim 10 , wherein machining is a process selected from the group consisting of electro-discharge machining and grinding.  
   
   
       14 . The method of  claim 10 , wherein the combined modified regions define a first hot gas valve segment in net or near-net shape.  
   
   
       15 . The method of  claim 14 , further comprising: 
 machining the first hot gas valve segment; and    repeating the forming, modifying, and machining steps to form additional valve segments continuous with the first hot gas valve segment until the combined modified regions define a completed hot gas valve in net or near-net shape.    
   
   
       16 . The method of  claim 10 , wherein the solid free-form fabrication process is an ion fusion formation process.  
   
   
       17 . A solid free-form fabrication method of manufacturing a hot gas valve for a divert and attitude control system in a propelled craft, the method comprising: 
 building a plurality of separate valve segments using a solid free-form fabrication process comprising the steps of: 
 forming successive feedstock layers by depositing the feedstock material into a predetermined region, the feedstock layers representing successive cross-sectional slices of the hot gas valve, and  
 modifying the feedstock by directing an energy source to the predetermined region and thereby creating modified regions in the successive feedstock layers, the combined modified regions defining a hot gas valve segment in net or near-net shape; and  
   assembling the plurality of separate valve segments to produce the hot gas valve in net or near-net shape.    
   
   
       18 . The method of  claim 17 , further comprising: 
 machining the hot gas valve segments after modifying the feedstock to bring the hot gas valve segments to final dimensions before assembling the plurality of separate valve segments.    
   
   
       19 . The method of  claim 17 , wherein machining is a process selected from the group consisting of electro-discharge machining and grinding.  
   
   
       20 . The method of  claim 17 , wherein the solid free-form fabrication process is an ion fusion formation process.