US 11,858,202 B2
System and method for performing laser powder bed fusion using controlled, supplemental in situ surface heating to control microstructure and residual stresses in formed part
William Smith, Oakland, CA (US); Gabriel M. Guss, Manteca, CA (US); Manyalibo Joseph Matthews, Livermore, CA (US); Joseph T. McKeown, Pleasanton, CA (US); and John Roehling, Livermore, CA (US)
Assigned to Lawrence Livermore National Security, LLC, Livermore, CA (US)
Filed by Lawrence Livermore National Security, LLC, Livermore, CA (US)
Filed on Mar. 26, 2019, as Appl. No. 16/365,029.
Prior Publication US 2020/0306884 A1, Oct. 1, 2020
Int. Cl. B29C 64/153 (2017.01); B23K 26/342 (2014.01); B33Y 30/00 (2015.01); B33Y 10/00 (2015.01); B33Y 50/02 (2015.01); B23K 26/06 (2014.01); B23K 26/066 (2014.01); B23K 26/073 (2006.01); B23K 26/08 (2014.01); B23K 26/60 (2014.01); B22F 10/28 (2021.01); B22F 12/10 (2021.01); B22F 12/41 (2021.01); B22F 12/45 (2021.01); B22F 10/38 (2021.01); B22F 12/44 (2021.01); B22F 12/49 (2021.01); B22F 10/36 (2021.01); B22F 10/368 (2021.01)
CPC B29C 64/153 (2017.08) [B22F 10/28 (2021.01); B22F 10/38 (2021.01); B22F 12/10 (2021.01); B22F 12/41 (2021.01); B22F 12/45 (2021.01); B23K 26/066 (2015.10); B23K 26/0608 (2013.01); B23K 26/0626 (2013.01); B23K 26/0643 (2013.01); B23K 26/0648 (2013.01); B23K 26/073 (2013.01); B23K 26/0884 (2013.01); B23K 26/342 (2015.10); B23K 26/60 (2015.10); B33Y 10/00 (2014.12); B33Y 30/00 (2014.12); B33Y 50/02 (2014.12); B22F 10/36 (2021.01); B22F 10/368 (2021.01); B22F 12/49 (2021.01)] 16 Claims
OG exemplary drawing
 
1. An additive manufacturing system for forming a part using a powder material, the system comprising:
a computer configured to generate an electronic mask sizing control signal;
a primary heat generating subsystem responsive to the computer for generating a fusing beam for heating and fusing at least one of a plurality of select portions of a powder layer, or an entire area of a powder layer, deposited on a build plate;
a beam steering subsystem responsive to the computer, and including a first mask, for steering the fusing beam over the powder layer deposited on the build plate;
a supplemental heating subsystem for generating a wide area beam to heat a portion of the powder layer;
the supplemental heating subsystem including a second mask forming a portion of a computer controllable mask subsystem, the computer controllable mask subsystem being responsive to the electronic mask sizing control signal from the computer and configured to control a dimension and a shape of the wide area beam independently of the fusing beam, to enable illuminating two selected areas of the powder layer on the build plate with differing selected intensities and different beam coverage areas, through use of the wide area beam and the fusing beam;
the computer controlling the supplemental heating subsystem while simultaneously controlling the primary heat generating subsystem, and further such that the supplemental heating subsystem heats the portion of the powder layer at least one of:
prior to fusing of powder of the powder layer with the fusing beam;
simultaneously with fusing of the powder of the powder layer with the fusing beam; or
subsequent to fusing of the powder of the powder layer with the fusing beam;
the wide area beam being of an intensity which is insufficient to fuse the powder layer; and
the wide area beam operating to alter a microstructure of the powder layer as the powder layer is at least one of:
fused by the fusing beam, or
as the powder layer cools after being fused by the fusing beam,
to relieve stress in the part produced by thermal gradients created during operation of the fusing beam fusing the powder layer, and to control an overall thermal history of the powder layer while being acted on by the fusing beam and the wide area beam.