Powder evacuation systems

Abstract

An additive manufacturing system includes a build chamber housing a recoater and a sintering laser. A build plate is moveable within the build chamber to accommodate growth of a part formed by the recoater and the sintering laser. At least one powder evacuation cavity at least partially surrounds a build volume of the build chamber. The build volume of the build chamber is defined between the build plate and the recoater and is configured to hold a sintered part and unsintered powder during an additive manufacturing build in the build chamber.

What is claimed is: 
     
         1 . A method of managing feedstock powder comprising:
 forming a part from feedstock powder in a powder bed within a build volume;   evacuating unsintered feedstock powder from the build volume, wherein the unsintered feedstock powder flows into at least one evacuation cavity at least partially surrounding the build volume.   
     
     
         2 . The method as recited in  claim 1 , wherein evacuating unsintered feedstock powder includes opening at least one gating valve to place the at least one powder evacuation cavity in fluid communication with the build volume. 
     
     
         3 . The method as recited in  claim 1 , wherein evacuating unsintered feedstock powder includes vibrating the build volume sub- or ultrasonically to facilitate flow of powder from the build volume into the at least one powder evacuation cavity. 
     
     
         4 . The method as recited in  claim 3 , wherein at least one of:
 vibrating includes vibrating in a direction lateral to build direction in the build volume; and/or   vibrating includes vibrating the build volume sub- or ultrasonically.   
     
     
         5 . The method as recited in  claim 1 , further comprising dosing feedstock powder into the build volume from a dosing chamber, wherein the dosing chamber and the at least one powder evacuation cavity are distinct and separate from one another. 
     
     
         6 . The method as recited in  claim 5 , further comprising recycling feedstock powder from the at least one evacuation cavity to the dosing chamber through a closed loop recycling system for re-use of the unsintered feedstock powder. 
     
     
         7 . The method as recited in  claim 6 , wherein recycling the feedstock powder includes maintaining the closed loop recycling system under a controlled atmosphere. 
     
     
         8 . The method as recited in  claim 1 , further comprising automatically controlling the at least one evacuation cavity to automatically initiate powder removal from the build volume after completing a build. 
     
     
         9 . The method as recited in  claim 1 , wherein evacuating unsintered feedstock powder from the build volume is performed after forming the part