Corrective capabilities of different rescanning strategies to restore microstructure and density of initially porous 316L laser powder bed fusion

Corrective capabilities of different rescanning strategies to restore microstructure and density of initially porous 316L laser powder bed fusion

LE SAINT Théo, KELLER Clément, ABROUG Foued, ARNAUD Lionel

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Abstract. Mechanical properties of Laser Power Bed Fusion (LPBF) parts, and particularly fatigue properties, are heavily affected by defects including surface roughness or porosity. To mitigate the occurrence of these defects, in-situ and on-line corrective measures can be implemented to the fabrication process, among them, rescanning, which consists in remelting an already solidified layer. Initially porous LPBF samples were created and then rescanned using different scanning parameters and strategies. Results show that it is possible to regain part’s health, compared to a standardly processed one, in terms of density, hardness and even improved roughness. This remelting process is known to refine microstructure of fabricated materials as well as reduce surface roughness and porosity without requiring further post-processing steps. Therefore, employing rescanning as a corrective technique appears to be a promising approach for rectifying detected defects during the fabrication process. The objective of this study is to assess the corrective capabilities of different rescanning strategies to restore the microstructure of an initially porous 316L LPBF simulating a defected part. This study shows that various rescanning strategies allow for densification of initially porous material from 98.83 ± 0.20 % to 99.75 ± 0.09 %, as well as lateral surface roughness reduction from Ra 20.2 ± 5.2 µm to Ra 12.7 ± 0.1 µm and microhardness increase from 243 ± 5 HV0.5 to 253 ± 3 HV0.5.

LPBF, Rescanning, 316L, Defects, Microstructure, Characterization

Published online 4/24/2024, 7 pages
Copyright © 2024 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: LE SAINT Théo, KELLER Clément, ABROUG Foued, ARNAUD Lionel, Corrective capabilities of different rescanning strategies to restore microstructure and density of initially porous 316L laser powder bed fusion, Materials Research Proceedings, Vol. 41, pp 242-248, 2024


The article was published as article 27 of the book Material Forming

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

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