Independently controllable powder delivery for additive manufacturing

Abstract

An additive manufacturing system that includes a platen, a feed material delivery system configured to deliver feed material to a location on the platen specified by a computer aided design program and a heat source configured to raise a temperature of the feed material simultaneously across all of the layer or across a region that extends across a width of the platen and scans the region across a length of the platen. The heat source can be an array of heat lamps, or a plasma source.

1 - 33 . (canceled) 
     
     
         34 . An additive manufacturing system, comprising:
 a platen to support an object to be fabricated;   a dispenser apparatus positioned above the platen to dispense a layer of powder over the platen, the dispenser apparatus including
 a common reservoir to hold the powder, 
 a plurality of openings for powder to flow from the common reservoir onto the platen, the plurality of openings extending along a first axis; and 
 a plurality of independently controllable gates to independently control flow of the powder through the plurality of openings; 
   a drive system to move the dispenser apparatus along a second axis perpendicular to the first axis; and   a heat source configured to selectively heat to the layer of feed material to a temperature sufficient to cause the powder to fuse.   
     
     
         35 . The system of  claim 34 , wherein each gate comprises a valve. 
     
     
         36 . The system of  claim 35 , wherein the valve is selected from the group consisting of a pneumatic valve, a microelectromechanical system (MEMS) valve, a solenoid valve and a magnetic valve. 
     
     
         37 . The system of  claim 34 , wherein each gate is configured to urge the powder out of an associated opening. 
     
     
         38 . The system of  claim 34 , wherein the plurality of openings extend across a width of the platen in the first axis. 
     
     
         39 . The system of  claim 34 , wherein the heat source is configured to generate a beam that is scanned across the platen and is modulated to control which voxels are fused. 
     
     
         40 . The system of  claim 39 , wherein the heat source comprises a laser and the beam is a laser beam. 
     
     
         41 . The system of  claim 40 , comprising a mirror galvanometer to scan the laser beam across the platen. 
     
     
         42 . The system of  claim 34 , comprising a roller movable parallel to the platen surface by a drive system and configured to compact the layer of powder. 
     
     
         43 . The system of  claim 34 , comprising a blade configured movable parallel to the platen surface by a drive system and configured to level the layer of powder. 
     
     
         44 . The system of  claim 34 , comprising a controller configured to cause the dispenser to dispense the powder material in a pattern specified in a computer-readable medium. 
     
     
         45 . The system of  claim 34 , comprising a housing enclosing a vacuum chamber, and wherein the platen and dispenser are positioned in the vacuum chamber. 
     
     
         46 . The system of  claim 34 , wherein the dispenser apparatus provides a first dispenser apparatus, and the system further comprises a second dispenser apparatus positioned above the platen to dispense a second powder over the platen. 
     
     
         47 . The system of  claim 46 , wherein the second dispenser apparatus includes
 a second common reservoir to hold the second powder,   a second plurality of openings for powder to flow from the second common reservoir onto the platen, the second plurality of openings extending along the first axis; and   a second plurality of independently controllable gates to independently control flow of the second powder through the second plurality of openings.   
     
     
         48 . The system of  claim 47 , wherein the second dispenser apparatus is positioned relative to the first dispenser apparatus such that the second plurality of openings of the second dispenser apparatus is spaced apart from the plurality of openings of the first dispenser apparatus along the second axis. 
     
     
         49 . A method of additive manufacturing, comprising:
 flowing a powder from a common reservoir through a plurality of openings in a dispenser apparatus positioned above the platen and onto the platen, the plurality of openings extending along a first axis,   moving the dispenser apparatus along a second axis perpendicular to the first axis; and   independently controlling a plurality of gates to independently control flow of the powder through the plurality of openings so as to selectively dispense a layer of the powder over the platen in a pattern specified in a computer-readable medium; and   selectively heating the layer of powder to a temperature sufficient to cause the powder to fuse.   
     
     
         50 . The method of  claim 49 , wherein selectively heating the layer of powder comprises generating a beam, scanning the beam across the platen, and modulating the beam to control which voxels are fused. 
     
     
         51 . The method of  claim 49 , wherein the beam is a laser beam. 
     
     
         52 . The method of  claim 51 , wherein scanning comprises scanning the laser beam with a mirror galvanometer. 
     
     
         53 . The method of  claim 49 , comprising compacting the layer of powder with a roller and moving the roller parallel to the platen surface. 
     
     
         54 . The method of  claim 49 , comprising leveling the layer of powder by moving a blade parallel to the platen surface.