Effects of shot sleeve pre-solidification on the microstructure and tensile properties of high pressure die cast AE44
File(s)
Published version
Author(s)
YU, Wenhao
Zhan, Hongyi
Gourlay, Christopher
Type
Journal Article
Abstract
In cold-chamber high pressure die casting (HPDC), some pre-solidification occurs in the shot
sleeve prior to being injected into the die cavity. Here, we study the effects of pre-solidification
on the development of microstructure and defects in the HPDC of magnesium alloy AE44
(Mg–4Al–4RE–0.2Mn, wt pct, where RE are mixed La and Ce) and on subsequent tensile
properties. Samples with a high fraction of pre-solidification contained both externally solidified
crystals (ESCs) and cold flakes, which also induced large pockets of positive macrosegregation.
Variations in the morphology and length scale of a-Mg grains and eutectic Al11RE3 are
discussed in terms of the different cooling conditions for each microstructural feature using a
grain morphology map for a-Mg. A high fraction of pre-solidification resulted in a small
decrease in yield stress due to the larger microstructural length scale, and a substantial decrease
in ultimate tensile strength and ductility due to the presence of a non-bonded interface between
cold flakes and the surrounding material. The results provide insights into microstructure
formation in the HPDC of AE44 and highlight the importance of controlling the extent of
pre-solidification that is injected into the die cavity.
sleeve prior to being injected into the die cavity. Here, we study the effects of pre-solidification
on the development of microstructure and defects in the HPDC of magnesium alloy AE44
(Mg–4Al–4RE–0.2Mn, wt pct, where RE are mixed La and Ce) and on subsequent tensile
properties. Samples with a high fraction of pre-solidification contained both externally solidified
crystals (ESCs) and cold flakes, which also induced large pockets of positive macrosegregation.
Variations in the morphology and length scale of a-Mg grains and eutectic Al11RE3 are
discussed in terms of the different cooling conditions for each microstructural feature using a
grain morphology map for a-Mg. A high fraction of pre-solidification resulted in a small
decrease in yield stress due to the larger microstructural length scale, and a substantial decrease
in ultimate tensile strength and ductility due to the presence of a non-bonded interface between
cold flakes and the surrounding material. The results provide insights into microstructure
formation in the HPDC of AE44 and highlight the importance of controlling the extent of
pre-solidification that is injected into the die cavity.
Date Issued
2024-06
Date Acceptance
2024-03-08
Citation
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, 2024, 55 (6), pp.2019-2033
ISSN
1073-5623
Publisher
Springer
Start Page
2019
End Page
2033
Journal / Book Title
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
Volume
55
Issue
6
Copyright Statement
© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
License URL
Identifier
https://link.springer.com/article/10.1007/s11661-024-07376-x
Publication Status
Published
Date Publish Online
2024-03-29