The Effect of Degassing on Grain Refinement in Commercial Purity Aluminum

Schaffer, P.L. and Dahle, A.K. (2009) The Effect of Degassing on Grain Refinement in Commercial Purity Aluminum. METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 40A 2: 481-485. doi:10.1007/s11661-008-9725-9


Author Schaffer, P.L.
Dahle, A.K.
Title The Effect of Degassing on Grain Refinement in Commercial Purity Aluminum
Journal name METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE   Check publisher's open access policy
ISSN 1073-5623
Publication date 2009-02
Year available 2009
Sub-type Article (original research)
DOI 10.1007/s11661-008-9725-9
Volume 40A
Issue 2
Start page 481
End page 485
Total pages 5
Editor Laughlin, D.E.
Place of publication United States
Publisher Springer New York LLC
Collection year 2010
Language eng
Subject C1
8612 Fabricated Metal Products
091207 Metals and Alloy Materials
Abstract Degassing of molten aluminum is used to remove dissolved hydrogen and impurity particles prior to casting. The most common method, rotary degassing, gives a small bubble size and distributes the bubbles throughout the melt by means of vigorous stirring. Although this is an efficient method for hydrogen removal, the purge gas may also inadvertently remove grain refining particles and thus reduce refinement efficiency. During degassing, particle removal occurs by physical attachment to the degassing bubbles and flotation, by turbulent transport due to the flow field generated by stirring, or by sedimentation. The experiments reported here were undertaken using a static graphite degassing lance (i.e., nonrotating) in order to prevent the formation of strong flow fields and to quantify the rate of grain refiner loss due to bubble attachment and floatation. By varying either (a) gas flow rate, (b) grain refiner addition level, or (c) type of grain refiner, it was found that, although grain size increased with time, the increase was predominantly due to particle sedimentation and not caused by attachment.
Keyword ALLOYS
Q-Index Code C1
Q-Index Status Confirmed Code

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2010 Higher Education Research Data Collection
School of Mechanical & Mining Engineering Publications
 
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Created: Thu, 03 Sep 2009, 08:59:39 EST by Mr Andrew Martlew on behalf of School of Mechanical and Mining Engineering