US 11,780,160 B2
Method of manufacturing a three-dimensional object
Anil K Sachdev, Rochester Hills, MI (US); Frederick E Pinkerton, Warren, MI (US); Raja K Mishra, Warren, MI (US); and Tyson W Brown, Royal Oak, MI (US)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on Jun. 3, 2021, as Appl. No. 17/337,863.
Application 17/337,863 is a division of application No. 15/977,545, filed on May 11, 2018, granted, now 11,031,161.
Prior Publication US 2021/0296027 A1, Sep. 23, 2021
Int. Cl. B29C 64/153 (2017.01); H01F 1/03 (2006.01); B29C 64/268 (2017.01); B33Y 70/00 (2020.01); B22F 10/28 (2021.01); B22F 10/38 (2021.01); B22F 10/50 (2021.01); B33Y 80/00 (2015.01); C01B 21/06 (2006.01); B22F 12/70 (2021.01); B22F 10/32 (2021.01); B22F 10/62 (2021.01)
CPC B29C 64/153 (2017.08) [B22F 10/28 (2021.01); B22F 10/38 (2021.01); B22F 10/50 (2021.01); B29C 64/268 (2017.08); B33Y 70/00 (2014.12); H01F 1/0311 (2013.01); B22F 10/32 (2021.01); B22F 10/62 (2021.01); B22F 12/70 (2021.01); B33Y 80/00 (2014.12); C01B 21/0622 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of manufacturing a three-dimensional object using a powder bed fusion additive manufacturing technique, the method comprising:
(a) providing a powder feed material including an alloy of iron (Fe) and carbon (C);
(b) distributing a layer of the powder feed material over a solid substrate;
(c) scanning selective regions of the layer of the powder feed material with a laser beam to locally melt the selective regions and form a pool of molten feed material, the selective regions of the layer corresponding to a cross-section of a three-dimensional object being formed;
(d) exposing the pool of molten feed material to gaseous carbon and gaseous nitrogen to dissolve carbide ions and nitride ions into the pool of molten feed material to produce a molten carbon and nitrogen-containing solution;
(e) terminating the laser beam to cool and solidify the molten carbon-containing solution into a solid layer of hardened steel; and
(f) repeating steps (b) through (e) to form a three-dimensional object made up of a plurality of solid layers of hardened steel,
wherein the plurality of solid layers of hardened steel comprise, by weight, 0.1% to 4% carbon and 0.01% to 0.5% nitrogen, and
wherein the plurality of solid layers of hardened steel exhibit a body-centered cubic crystal structure or a face-centered cubic crystal structure.