eprintid: 10205876
rev_number: 7
eprint_status: archive
userid: 699
dir: disk0/10/20/58/76
datestamp: 2025-03-11 11:28:08
lastmod: 2025-03-11 11:28:08
status_changed: 2025-03-11 11:28:08
type: article
metadata_visibility: show
sword_depositor: 699
creators_name: Fan, Xianqiang
creators_name: Fleming, Tristan G
creators_name: Clark, Samuel J
creators_name: Fezzaa, Kamel
creators_name: Getley, Anna CM
creators_name: Marussi, Sebastian
creators_name: Wang, Hongze
creators_name: Leung, Chu Lun Alex
creators_name: Kao, Andrew
creators_name: Lee, Peter D
title: Magnetic modulation of keyhole instability during laser welding and additive manufacturing
ispublished: pub
divisions: UCL
divisions: B02
divisions: B04
divisions: C07
divisions: D08
divisions: F45
note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
abstract: Keyhole instability during laser welding and laser powder bed fusion (LPBF) can cause keyhole collapse and pore formation. Using high-speed x-ray imaging, we demonstrate that the flow vortex-induced protrusion on the rear keyhole wall is crucial in initiating keyhole instability. Applying a transverse magnetic field suppresses the keyhole instability by driving a secondary thermoelectric magnetohydrodynamics (TEMHD) flow that alters the net flow vortex. This minimizes protrusions and large-amplitude keyhole oscillations. The suppression effectiveness depends on the laser scanning direction relative to the magnetic field orientation because this controls the Seebeck effect-induced Lorentz force's direction. We show that at LPBF length scales, electromagnetic damping is weak, and for alloys with a large Seebeck coefficient, TEMHD becomes the dominant mechanism controlling flow behind the keyhole.
date: 2025-02-21
date_type: published
publisher: American Association for the Advancement of Science (AAAS)
official_url: https://doi.org/10.1126/science.ado8554
oa_status: green
full_text_type: other
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 2363813
doi: 10.1126/science.ado8554
medium: Print-Electronic
lyricists_name: Getley, Anna
lyricists_name: Lee, Peter
lyricists_name: Leung, Chu Lun Alex
lyricists_name: Marussi, Sebastian
lyricists_name: Fan, Xianqiang
lyricists_name: Fan, Xiaochen
lyricists_id: ACMGE89
lyricists_id: PLEEX57
lyricists_id: CLALE63
lyricists_id: SMARU59
lyricists_id: XFANX55
lyricists_id: XFANX05
actors_name: Lee, Peter
actors_id: PLEEX57
actors_role: owner
full_text_status: public
publication: Science
volume: 387
number: 6736
pagerange: 864-869
event_location: United States
issn: 0036-8075
citation:        Fan, Xianqiang;    Fleming, Tristan G;    Clark, Samuel J;    Fezzaa, Kamel;    Getley, Anna CM;    Marussi, Sebastian;    Wang, Hongze;             ... Lee, Peter D; + view all <#>        Fan, Xianqiang;  Fleming, Tristan G;  Clark, Samuel J;  Fezzaa, Kamel;  Getley, Anna CM;  Marussi, Sebastian;  Wang, Hongze;  Leung, Chu Lun Alex;  Kao, Andrew;  Lee, Peter D;   - view fewer <#>    (2025)    Magnetic modulation of keyhole instability during laser welding and additive manufacturing.                   Science , 387  (6736)   pp. 864-869.    10.1126/science.ado8554 <https://doi.org/10.1126/science.ado8554>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10205876/1/J396_Fan_Science_2024_as_sub.pdf