Apparatus and methods for manufacturing

Abstract

One variation of a method for fusing and annealing powered material within an apparatus for manufacturing includes: depositing a layer of powdered material across a build platform; at a first time, projecting a first energy beam of a first power density onto an area of the layer of powdered material; and at a second time succeeding the first time, projecting a second energy beam of a second power density less than the first power density onto the area.

We claim: 
     
         1 . A method for fusing and annealing powered material within an apparatus for manufacturing, the method comprising:
 depositing a layer of powdered material across a build platform;   at a first time, projecting a first energy beam of a first power density onto an area of the layer of powdered material; and   at a second time succeeding the first time, projecting a second energy beam of a second power density less than the first power density onto the area.   
     
     
         2 . The method of  claim 1 , wherein projecting the first energy beam onto the area comprises generating the first energy beam at a first laser diode, focusing the first energy beam onto the layer of powdered material, and displacing the first energy beam across the layer of powdered material along a first direction, and wherein projecting the second energy beam onto the area comprises generating the second energy beam at a second laser diode substantially simultaneously with the first energy beam, focusing the second energy beam onto the layer of powdered material adjacent the first energy beam, and displacing the second energy beam along the first direction behind the first energy beam. 
     
     
         3 . The method of  claim 2 , further comprising generating a third energy beam at a third laser diode substantially simultaneously with the first energy beam, focusing the third energy beam onto the layer of powdered material adjacent the first energy beam, and displacing the third energy beam along the first direction ahead of the first energy beam, the third energy beam of a power density less than the first power density. 
     
     
         4 . The method of  claim 2 , further comprising generating a third energy beam at a third laser diode substantially simultaneously with the first energy beam, focusing the third energy beam onto the layer of powdered material adjacent the second energy beam, and displacing the third energy beam along the direction behind the second energy beam, the third energy beam of a power density less than the second power density. 
     
     
         5 . The method of  claim 2 , wherein projecting the first energy beam onto the area and projecting the second energy beam onto the area comprise displacing the first energy beam and the second energy beam across the layer of powdered material along the first direction during a first period of time comprising the first time and the second time, and further comprising displacing the first energy beam and the second energy beam across the layer of powdered material along a second direction during a second period of time succeeding the first period of time, the second direction opposite the first direction, the second energy beam of a power density at the layer of powdered material greater than a power density of the first beam at the layer of powdered material during the second period of time. 
     
     
         6 . The method of  claim 1 , wherein projecting the first energy beam onto the area comprises displacing the first energy beam linearly across the area at a first speed to fuse powdered material within the area, and wherein projecting the second energy beam onto the area comprises displacing the second energy beam linearly across the area at a second speed less than the first speed to anneal fused material within the area. 
     
     
         7 . The method of  claim 1 , wherein projecting the first energy beam onto the area comprises scanning the first energy beam across the layer of powdered material during a first period of time comprising the first time, and wherein projecting the second energy beam onto the area comprises scanning the second energy beam across the layer of powdered material during a second period of time comprising the second time and succeeding the first period of time. 
     
     
         8 . The method of  claim 7 , further comprising depositing a second layer of powdered material over the layer of powdered material and, at a third time succeeding the second time, projecting a third energy beam onto a second area of the second layer adjacent the area. 
     
     
         9 . The method of  claim 1 , wherein projecting the first energy beam onto the area comprises focusing the first energy beam onto a first spot coincident with the area of the layer of powdered material, and wherein projecting the second energy beam onto the area comprises focusing the second energy beam onto a second spot coincident with the area of the layer of powdered material, the first spot bounded by the second spot. 
     
     
         10 . The method of  claim 9 , wherein projecting the first energy beam onto the area comprises generating the first beam of a first wavelength, and wherein projecting the second energy beam onto the area comprises generating the second beam of a second wavelength different than the first wavelength. 
     
     
         11 . The method of  claim 9 , wherein projecting the first energy beam onto the area comprises projecting the first energy beam onto the first spot of effective center at a first distance from an effective center of the second spot at the first time and projecting the first energy beam onto the first spot of effective center at a second distance from the effective center of the second spot at the second time, the first distance greater than the second distance. 
     
     
         12 . The method of  claim 9 , wherein projecting the first energy beam onto the area comprises collimating a Gaussian beam with a flattop refractive beam shaper. 
     
     
         13 . The method of  claim 1 , wherein projecting the first energy beam onto the area comprises generating the first energy beam at a laser diode, focusing the first energy beam onto a rotating mirror arranged over the build platform, and projecting the first energy beam through an F-theta lens and onto the area. 
     
     
         14 . The method of  claim 1 , further comprising detecting a temperature of the area during the first time and adjusting the second power density during the second time based on the temperature. 
     
     
         15 . The method of  claim 1 , wherein projecting the first energy beam onto the layer of powdered material comprises focusing an intermittent beam onto the layer of powdered material according to a digital build file. 
     
     
         16 . A method for fusing and annealing powered material within an apparatus for manufacturing, the method comprising:
 depositing a layer of powdered material across a build platform;   projecting a first energy beam along a first direction across the layer of powdered material, the first energy beam of a first power density at the layer of powdered material;   projecting a second energy beam across the layer of powdered material, the second energy beam trailing the first energy beam and of a second power density at the layer of powdered material greater than the first power density; and   projecting a third energy beam across the layer of powdered material, the third energy beam trailing the first energy beam and the second energy beam and of a third power density at the layer of powdered material less than the first power density.   
     
     
         17 . The method of  claim 16 , wherein projecting the first energy beam across the layer of powdered material comprises selectively preheating areas of the layer of powdered material with the first energy beam, wherein projecting the second energy beam across the layer of powdered material comprises selectively fusing areas of the layer of powdered material with the second energy beam, and wherein projecting the third energy beam across the layer of powdered material comprises selectively annealing areas of the layer of powdered material with the third energy beam. 
     
     
         18 . The method of  claim 16 , wherein projecting the first energy beam across the layer of powdered material comprises generating the first energy beam of a first wavelength, wherein projecting the second energy beam across the layer of powdered material comprises generating the second energy beam of a second wavelength different than the first wavelength, and wherein projecting the third energy beam across the layer of powdered material comprises generating the third energy beam of a third wavelength different than the first wavelength and the second wavelength. 
     
     
         19 . The method of  claim 16 , further comprising detecting a temperature of the area during the first time and adjusting the second power density during the second time based on the temperature and a target fuse temperature of the powdered material. 
     
     
         20 . The method of  claim 16 , wherein projecting the first energy beam along the first direction comprises focusing a first discrete laser beam through a first laser output optic, wherein projecting the second energy beam along the first direction comprises focusing a second discrete laser beam through a second laser output optic, and wherein projecting the third energy beam along the first direction comprises focusing a third discrete laser beam through a third laser output optic ganged with the first laser output optic and the second laser output optic, and further comprising, in response to a travel workspace limit in the first direction, indexing the first laser output optic, the second laser output optic, and the third laser output optic in a second direction perpendicular to the first direction. 
     
     
         21 . The method of  claim 16 , further comprising projecting a fourth energy beam and a fifth energy beam onto the layer of powdered material and focusing the first energy beam, the second energy beam, the third energy beam, the fourth energy beam, and the fifth energy beam onto a square array of spots onto the layer of powder material.