US 11,858,040 B2
Method of inspecting printing quality of 3D printing object using femtosecond laser beam during 3D printing process, and apparatus and 3D printing system for the same
Hoon Sohn, Daejeon (KR); and Peipei Liu, Daejeon (KR)
Assigned to Korea Advanced Institute of Science and Technology, Daejeon (KR)
Filed by Korea Advanced Institute of Science and Technology, Daejeon (KR)
Filed on Dec. 21, 2020, as Appl. No. 17/128,658.
Claims priority of application No. 10-2019-0179187 (KR), filed on Dec. 31, 2019.
Prior Publication US 2021/0197279 A1, Jul. 1, 2021
Int. Cl. B22F 10/36 (2021.01); B33Y 10/00 (2015.01); B33Y 30/00 (2015.01); B33Y 50/02 (2015.01); B22F 12/43 (2021.01); B22F 10/25 (2021.01); G01B 17/02 (2006.01); G01N 29/04 (2006.01); G01N 29/24 (2006.01); G01N 29/44 (2006.01); G01N 21/17 (2006.01); G01N 29/07 (2006.01)
CPC B22F 10/36 (2021.01) [B22F 10/25 (2021.01); B22F 12/43 (2021.01); B33Y 10/00 (2014.12); B33Y 30/00 (2014.12); B33Y 50/02 (2014.12); G01B 17/02 (2013.01); G01N 21/1702 (2013.01); G01N 29/043 (2013.01); G01N 29/07 (2013.01); G01N 29/2418 (2013.01); G01N 29/44 (2013.01); G01N 2021/1706 (2013.01); G01N 2291/011 (2013.01); G01N 2291/0231 (2013.01); G01N 2291/0289 (2013.01); G01N 2291/02827 (2013.01); G01N 2291/02854 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of inspecting a printing quality of a 3D printing object, including:
performing a 3D printing process by irradiating a printing laser beam generated by a 3D printing laser source onto a base material supplied to the printing object;
generating a femtosecond laser beam by a femtosecond laser source to perform estimation of physical property of the printing object and detection of defects of the printing object in real-time while the 3D printing process is being performed;
separating the femtosecond laser beam generated from the femtosecond laser source into a pump laser beam and a probe laser beam;
generating an ultrasonic wave by exciting the printing object by the printing laser beam irradiated from the 3D printing laser source or by irradiating the separated pump laser beam onto the printing object;
irradiating the probe laser beam onto a solidified region of the printing object to measure the ultrasonic wave;
detecting the probe laser beam reflected by the printing object to be converted into an electric signal; and
inspecting the printing quality of the printing object, including estimating a physical property of the printing object and detecting a defect of the printing object, by analyzing an amplitude and a phase of the converted electrical signal,
wherein the printing laser beam, and the pump laser and the probe laser beam separated from the femtosecond laser beam are aligned coaxially with each other and applied to the printing object, and
wherein the printing quality of the 3D printing object is inspected in real time using the femtosecond laser beam during the 3D printing process.