Numerical investigation into cleanability of support structures produced by powder bed fusion technology
ISSN: 1355-2546
Article publication date: 8 September 2021
Issue publication date: 18 March 2022
Abstract
Purpose
Support structures used in laser powder bed fusion are often difficult to clean from unsintered powder at the end of the process. This issue can be significantly reduced through a proper design of these auxiliary structures. This paper aims to investigate preliminary the airflow within differently oriented support structures and to provide design guidelines to enhance their cleanability, especially the depowdering of them.
Design/methodology/approach
This study investigates the cleanability of support structures in powder bed fusion technology. Digital models of cleaning operations were designed through computer-aided engineering systems. Simulations of the airflow running into the powder entrapped within the thin walls of auxiliary supports were implemented by computational fluid dynamics. This approach was applied to a set of randomly generated geometrical configurations to determine the air turbulence intensity depending on their design.
Findings
The results, which are based on the assumption that a relationship exists between turbulence and powder removal effectiveness, demonstrated that the maximum cleanability is obtainable through specific relative rotations between consecutive support structures. Furthermore, it was possible to highlight the considerable influence of the auxiliary structures next to the fluid inlet. These relevant findings establish optimal design rules for the cleanability of parts manufactured by powder bed fusion processes.
Originality/value
This study presents a preliminary investigation into the cleanability of support structures in laser powder bed fusion, which has not been addressed by previous literature. The results allow for a better understanding of the fluid dynamics during cleaning operations. New guidelines to enhance the cleanability of support structures are provided based on the results of simulations.
Keywords
Acknowledgements
The authors would like to thank the Fraunhofer Institut für Produktionsanlagen und Konstruktionstechnik, Fertigungstechnologien (IPK) and the Department of Industrial Engineering (DIN) at University of Bologna for software facilities and funding this joint research activity.
The simulation data are available on request.
Author disclosure statement: No competing financial interests exist.
Citation
Campana, G., Uhlmann, E., Mele, M., Raffaelli, L., Bergmann, A., Kochan, J. and Polte, J. (2022), "Numerical investigation into cleanability of support structures produced by powder bed fusion technology", Rapid Prototyping Journal, Vol. 28 No. 3, pp. 445-452. https://doi.org/10.1108/RPJ-02-2021-0039
Publisher
:Emerald Publishing Limited
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