Variable beam geometry laser-based powder bed fusion

Abstract

Systems and methods of adapting the geometrical shape of a laser beam in laser-based powder-bed fusion (PBF) are provided. An apparatus for laser-based powder-bed fusion includes a depositor that deposits a plurality of layers of a powder material. The apparatus further includes a laser beam source that generates a laser beam having a variable beam geometry. A laser application component applies the laser beam in one of a plurality of beam geometries to fuse the powder material to construct a build piece.

What is claimed is: 
     
         1 . An apparatus for laser-based powder-bed fusion, comprising:
 a depositor that deposits a plurality of layers of a powder material;   a laser beam source that generates a laser beam; and   a beam shaping component that shapes the laser beam into one of a plurality of beam geometries to fuse the powder material.   
     
     
         2 . The apparatus of  claim 1 , wherein the beam shaping component is configured to vary a beam geometry of the laser beam from the laser beam source during application of the laser beam. 
     
     
         3 . The apparatus of  claim 1 , wherein a laser beam geometry is varied based on a design profile for an object to be produced. 
     
     
         4 . The apparatus of  claim 1 , wherein a laser beam geometry is varied based on an energy profile for an object to be produced. 
     
     
         5 . The apparatus of  claim 1 , wherein a beam geometry of the laser beam comprises a two-dimensional shape. 
     
     
         6 . The apparatus of  claim 1 , wherein a beam geometry of the laser beam comprises a line. 
     
     
         7 . The apparatus of  claim 6 , wherein a length of the line is variable based on an energy profile of the laser beam. 
     
     
         8 . The apparatus of  claim 1 , wherein a beam geometry includes at least a first portion and a second portion and an energy profile of the first portion is different from an energy profile of the second portion. 
     
     
         9 . The apparatus of  claim 8 , wherein the energy profile of the first portion and the energy profile of the second portion are configured based at least in part on a temperature profile. 
     
     
         10 . The apparatus of  claim 8 , wherein the laser beam source is configured to provide a constant energy flux between the first portion and the second portion. 
     
     
         11 . The apparatus of  claim 8 , wherein the first portion is configured to preheat the powder material and the second portion is configured to fuse the powder material. 
     
     
         12 . The apparatus of  claim 8 , wherein the first portion is configured to fuse the powder material and the second portion is configured to reduce an energy flux to control cooling of the fused powder material. 
     
     
         13 . The apparatus of  claim 1 , further comprising a controller coupled to the laser beam source and configured to control a power density of a laser beam emitted from the laser beam source. 
     
     
         14 . The apparatus of  claim 1 , wherein a laser beam geometry is varied based on a temperature profile for an object to be produced. 
     
     
         15 . The apparatus of  claim 1 , wherein the beam shaping component comprises at least one of each of a fixed optical element and a movable optical element aligned to encompass the laser beam. 
     
     
         16 . The apparatus of  claim 15 , wherein at least one of the optical elements comprises a lens. 
     
     
         17 . A method of laser-based powder-bed fusion, comprising:
 adapting a geometry of a laser beam to form an adapted laser beam comprising a line or a two dimensional shape upon contacting a surface of a layer of powder material; and   applying the adapted laser beam to at least a portion of the layer of powder material to fuse at least a portion of a defined build piece.   
     
     
         18 . The method of  claim 17 , further comprising varying the geometry of the laser beam over time during application of the laser beam. 
     
     
         19 . The method of  claim 17 , further comprising varying the geometry of the laser beam based on an energy profile for an object to be produced. 
     
     
         20 . The method of  claim 17 , wherein a laser beam geometry of the adapted laser beam comprises a two-dimensional shape. 
     
     
         21 . The method of  claim 17 , wherein a laser beam geometry of the adapted laser beam comprises the line, the method further comprising applying the adapted laser beam in a direction perpendicular to a length of the line. 
     
     
         22 . The method of  claim 21 , further comprising varying a length of the line based on an energy profile of the adapted laser beam. 
     
     
         23 . The method of  claim 17 , wherein a laser beam geometry of the adapted laser beam includes at least a first portion and a second portion and an energy profile of the first portion is different than the energy profile of the second portion. 
     
     
         24 . The method of  claim 23 , wherein the energy profile of the first portion and the energy profile of the second portion are configured based at least in part on a temperature profile. 
     
     
         25 . The method of  claim 23 , wherein the energy profile of the first portion and the energy profile of the second portion are configured to provide a constant energy flux between the first portion and the second portion. 
     
     
         26 . The method of  claim 23 , wherein the first portion is configured to preheat the powder material and the second portion is configured to fuse the powder material. 
     
     
         27 . The method of  claim 23 , wherein the first portion is configured to fuse the powder material and the second portion is configured to reduce an energy flux to control cooling of the fused powder material. 
     
     
         28 . The method of  claim 17 , further comprising determining a geometry of the defined build piece, and wherein the geometry of the laser beam is adapted based on the geometry of the defined build piece.