Flow rate of metal powders at reduced and elevated air pressure
Flow rate of metal powders at reduced and elevated air pressure
There are suggestions that the flow rate of dry powder is affected by ambient gas pressure as distinct from pressure differential. This raises the concern that computer controlled powder deposition methods for selective laser sintering in which powder mixtures are delivered to the building platform by acoustic control of flow in capillaries may be affected by partial vacuum applied to reduce oxidation. The flow rate of free flowing powders in the static Hall flow meter was measured at reduced and elevated air pressure. There was no systematic difference in the Hall flow times for these powders over 8 orders of magnitude of pressure in the range from 2.0 × 105 Pa down to 8.1 × 10? 4 Pa. Copper powder as well as a tool steel was investigated because of the suggestion that flow reduction could be due to welding of asperities but flow rate reduction was not observed at reduced pressure down to 10? 4 Pa.
powder flow, vacuum, pressure, selective laser sintering
95-98
Yang, Shoufeng
e0018adf-8123-4a54-b8dd-306c10ca48f1
Evans, Julian R.G.
4eee463a-4dd3-4ef2-b9bc-784246b68ad2
6 July 2005
Yang, Shoufeng
e0018adf-8123-4a54-b8dd-306c10ca48f1
Evans, Julian R.G.
4eee463a-4dd3-4ef2-b9bc-784246b68ad2
Yang, Shoufeng and Evans, Julian R.G.
(2005)
Flow rate of metal powders at reduced and elevated air pressure.
Powder Technology, 154 (2-3), .
(doi:10.1016/j.powtec.2005.04.038).
Abstract
There are suggestions that the flow rate of dry powder is affected by ambient gas pressure as distinct from pressure differential. This raises the concern that computer controlled powder deposition methods for selective laser sintering in which powder mixtures are delivered to the building platform by acoustic control of flow in capillaries may be affected by partial vacuum applied to reduce oxidation. The flow rate of free flowing powders in the static Hall flow meter was measured at reduced and elevated air pressure. There was no systematic difference in the Hall flow times for these powders over 8 orders of magnitude of pressure in the range from 2.0 × 105 Pa down to 8.1 × 10? 4 Pa. Copper powder as well as a tool steel was investigated because of the suggestion that flow reduction could be due to welding of asperities but flow rate reduction was not observed at reduced pressure down to 10? 4 Pa.
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Published date: 6 July 2005
Additional Information:
Short communication
Keywords:
powder flow, vacuum, pressure, selective laser sintering
Organisations:
Engineering Mats & Surface Engineerg Gp
Identifiers
Local EPrints ID: 165077
URI: http://eprints.soton.ac.uk/id/eprint/165077
ISSN: 0032-5910
PURE UUID: babdef82-b174-4743-b6bb-723f31d1b8e3
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Date deposited: 07 Oct 2010 13:59
Last modified: 14 Mar 2024 02:09
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Author:
Julian R.G. Evans
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