Fouda, YM and Bayly, AE orcid.org/0000-0001-6354-9015 (2020) A DEM study of powder spreading in additive layer manufacturing. Granular Matter, 22 (1). 10. ISSN 1434-5021
Abstract
In this paper, discrete element method simulations were used to study the spreading of an idealised, blade based, powder coating system representative of the spreading of spherical, mono-sized, non-cohesive titanium alloy (Ti6AlV4) particles in additive layer manufacturing applications. A vertical spreader blade was used to accelerate a powder heap across a horizontal surface, with a thin gap between the blade and the surface, resulting in the deposition of a thin powder layer. The results showed that it is inevitable to deposit a powder layer with a lower packing fraction than the initial powder heap due to three mechanisms: shear-induced dilation during the initiation of powder motion by the spreader; dilation and rearrangement due to powder motion through the gap; and the inertia of the particles in the deposited powder layer. It was shown that the process conditions control the contribution of these three mechanisms, and that the velocity profile in the shear layer in front of the gap is critical to the final deposited layer packing fraction. The higher the mean normalised velocity in the shear layer the lower the deposited layer packing fraction. The gap thickness and the spreader blade velocity affect the properties of the deposited layer; with the former increasing its packing fraction and the latter decreasing it. The analysis presented in this study could be adapted to powders of different materials, morphologies and surface properties.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author(s), 2019. This is an open access article under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
Keywords: | Additive manufacturing (AM); Powder spreading; Discrete element method (DEM); Dilation; Metal powders; Powder bed fusion |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Funding Information: | Funder Grant number Innovate UK fka Technology Strategy Board (TSB) 113051 EPSRC (Engineering and Physical Sciences Research Council) EP/P006566/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 17 Mar 2020 11:35 |
Last Modified: | 17 Mar 2020 11:36 |
Status: | Published |
Publisher: | Springer Verlag |
Identification Number: | 10.1007/s10035-019-0971-x |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:158486 |
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Filename: VOR Fouda-Bayly2019_Article_ADEMStudyOfPowderSpreadingInAd.pdf
Licence: CC-BY 4.0