US 12,459,038 B2
Additive manufacturing method
Hirotsugu Kawanaka, Tokyo (JP); Noboru Saito, Tokyo (JP); and Shinji Matsushita, Tokyo (JP)
Assigned to HITACHI, LTD., Tokyo (JP)
Appl. No. 18/013,301
Filed by HITACHI, LTD., Tokyo (JP)
PCT Filed Mar. 8, 2021, PCT No. PCT/JP2021/009091
§ 371(c)(1), (2) Date Dec. 28, 2022,
PCT Pub. No. WO2022/030042, PCT Pub. Date Feb. 10, 2022.
Claims priority of application No. 2020-131646 (JP), filed on Aug. 3, 2020.
Prior Publication US 2023/0321728 A1, Oct. 12, 2023
Int. Cl. B22F 10/32 (2021.01); B22F 10/28 (2021.01); B22F 12/17 (2021.01); B22F 12/30 (2021.01); B29C 64/153 (2017.01); B29C 64/245 (2017.01); B29C 64/295 (2017.01); B29C 64/371 (2017.01); B33Y 10/00 (2015.01)
CPC B22F 10/32 (2021.01) [B22F 10/28 (2021.01); B22F 12/17 (2021.01); B22F 12/30 (2021.01); B29C 64/153 (2017.08); B29C 64/245 (2017.08); B29C 64/295 (2017.08); B29C 64/371 (2017.08); B33Y 10/00 (2014.12); B22F 2201/11 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An additive manufacturing method of forming a powder bed on a stage in a chamber and emitting a laser beam onto the powder bed to manufacture a shaped object by fusion, the additive manufacturing method comprising:
reducing a pressure inside the chamber to a pressure equal to or higher than 8000 [Pa] and equal to or lower than 30,000 [Pa]; and
forming the powder bed on the stage while preheating the stage and supplying an inert gas,
wherein when a pressure variation of 300 [Pa] or higher is measured in 180 [s] in the chamber during additive manufacturing in which formation of the powder bed and the fusion are repeated, and vacuumizing of the chamber and adjustment of an oxygen amount and a pressure in the chamber are executed after the fusion at measurement of the pressure variation is completed.