Direct observation of pore formation mechanisms during LPBF additive manufacturing process and high energy density laser welding
Abstract
Laser powder bed fusion (LPBF) is a 3D printing technology that can print parts with complex geometries that are unachievable by conventional manufacturing technologies. However, pores formed during the printing process impair the mechanical performance of the printed parts, severely hindering their widespread application. Here, we report six pore formation mechanisms that were observed during the LPBF process. Our results in this study reconfirm three pore formation mechanisms - keyhole induced pores, pore formation from feedstock powder and pore formation along the melting boundary during laser melting from vaporization of a volatile substance or an expansion of a tiny trapped gas. We also observe three new pore formation mechanisms: (1) pore trapped by surface fluctuation, (2) pore formation due to depression zone fluctuation when the depression zone is shallow and (3) pore formation from a crack. The results presented here provide direct evidence and insight into pore formation mechanisms during the LPBF process, which may guide the development of pore elimination/mitigation approaches. Since certain laser processing conditions studied here are similar to the situations in high energy density laser welding, the results presented here also have implications for laser welding.
- Authors:
-
- Missouri Univ. of Science and Technology, Rolla, MO (United States); Univ. of Wisconsin, Madison, WI (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Univ. of Wisconsin, Madison, WI (United States)
- Missouri Univ. of Science and Technology, Rolla, MO (United States)
- Kansas City National Security Campus (KCNSC), Kansas City, MO (United States)
- Univ. of Virginia, Charlottesville, VA (United States)
- Publication Date:
- Research Org.:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Org.:
- USDOE Office of Enterprise Assessments (EA); National Science Foundation (NSF)
- OSTI Identifier:
- 1762694
- Alternate Identifier(s):
- OSTI ID: 1782735
- Grant/Contract Number:
- AC02-06CH11357; NA0002839
- Resource Type:
- Accepted Manuscript
- Journal Name:
- International Journal of Machine Tools and Manufacture
- Additional Journal Information:
- Journal Volume: 153; Journal ID: ISSN 0890-6955
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 42 ENGINEERING; additive manufacturing; laser powder bed fusion; laser welding; pore formation; x-ray imaging
Citation Formats
Hojjatzadeh, S. H., Parab, Niranjan D., Guo, Qilin, Qu, Minglei, Xiong, Lianghua, Zhao, Cang, Escano, Luis I., Fezzaa, Kamel, Everhart, Wes, Sun, Tao, and Chen, Lianyi. Direct observation of pore formation mechanisms during LPBF additive manufacturing process and high energy density laser welding. United States: N. p., 2020.
Web. doi:10.1016/j.ijmachtools.2020.103555.
Hojjatzadeh, S. H., Parab, Niranjan D., Guo, Qilin, Qu, Minglei, Xiong, Lianghua, Zhao, Cang, Escano, Luis I., Fezzaa, Kamel, Everhart, Wes, Sun, Tao, & Chen, Lianyi. Direct observation of pore formation mechanisms during LPBF additive manufacturing process and high energy density laser welding. United States. https://doi.org/10.1016/j.ijmachtools.2020.103555
Hojjatzadeh, S. H., Parab, Niranjan D., Guo, Qilin, Qu, Minglei, Xiong, Lianghua, Zhao, Cang, Escano, Luis I., Fezzaa, Kamel, Everhart, Wes, Sun, Tao, and Chen, Lianyi. Wed .
"Direct observation of pore formation mechanisms during LPBF additive manufacturing process and high energy density laser welding". United States. https://doi.org/10.1016/j.ijmachtools.2020.103555. https://www.osti.gov/servlets/purl/1762694.
@article{osti_1762694,
title = {Direct observation of pore formation mechanisms during LPBF additive manufacturing process and high energy density laser welding},
author = {Hojjatzadeh, S. H. and Parab, Niranjan D. and Guo, Qilin and Qu, Minglei and Xiong, Lianghua and Zhao, Cang and Escano, Luis I. and Fezzaa, Kamel and Everhart, Wes and Sun, Tao and Chen, Lianyi},
abstractNote = {Laser powder bed fusion (LPBF) is a 3D printing technology that can print parts with complex geometries that are unachievable by conventional manufacturing technologies. However, pores formed during the printing process impair the mechanical performance of the printed parts, severely hindering their widespread application. Here, we report six pore formation mechanisms that were observed during the LPBF process. Our results in this study reconfirm three pore formation mechanisms - keyhole induced pores, pore formation from feedstock powder and pore formation along the melting boundary during laser melting from vaporization of a volatile substance or an expansion of a tiny trapped gas. We also observe three new pore formation mechanisms: (1) pore trapped by surface fluctuation, (2) pore formation due to depression zone fluctuation when the depression zone is shallow and (3) pore formation from a crack. The results presented here provide direct evidence and insight into pore formation mechanisms during the LPBF process, which may guide the development of pore elimination/mitigation approaches. Since certain laser processing conditions studied here are similar to the situations in high energy density laser welding, the results presented here also have implications for laser welding.},
doi = {10.1016/j.ijmachtools.2020.103555},
journal = {International Journal of Machine Tools and Manufacture},
number = ,
volume = 153,
place = {United States},
year = {Wed Apr 08 00:00:00 EDT 2020},
month = {Wed Apr 08 00:00:00 EDT 2020}
}
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