Effect of solidification microstructure and Ca additions on creep strength of magnesium alloy AZ91 processed by Thixomolding

Beitrag in einer Fachzeitschrift
(Originalarbeit)


Details zur Publikation

Autor(en): Eibisch H, Lohmüller A, Kömpel N, Singer R
Zeitschrift: International Journal of Materials Research
Jahr der Veröffentlichung: 2008
Band: 99
Heftnummer: 1
Seitenbereich: 56-66
ISSN: 1862-5282
Sprache: Englisch


Abstract


The compressive creep behaviour of AZ91 processed by Thixomolding with varying solid phase content (2-45%) was investigated. It can be shown that with increasing solid phase content the creep rate at 150°C is reduced by a factor of 3-10. The results can be rationalised in terms of a grain size effect. The solid phase (primary α-Mg phase solidified prior to mould filling) is relatively coarse (40 um), i. e. the average grain size increases significantly when the material is processed in the semi-solid regime. Grain boundary sliding which is known to contribute significantly to creep deformation depends on the grain size. The creep rate of high pressure die cast material is found to be similar to thixomolded material. The high pressure die cast materials although nominally processed in the fully liquid regime, contains pre-solidified coarse primary α-Mg phase as well. The coarse solid phase particles are formed early in the process when the melt cools rapidly in the shot sleeve. AZ91 with Ca-additions up to 5 wt.% were prepared using a newly developed second feeding system that allows the addition of a second sort of granules to the screw in parallel to the main feed. As expected, Ca increases the creep strength very significantly. The reasons for this increase will be discussed. © Carl Hanser Verlag GmbH & Co. KG.



FAU-Autoren / FAU-Herausgeber

Kömpel, Natalie
Lehrstuhl für Werkstoffwissenschaften (Werkstoffkunde und Technologie der Metalle)
Lohmüller, Andreas
Lehrstuhl für Werkstoffwissenschaften (Werkstoffkunde und Technologie der Metalle)
Singer, Robert Prof. Dr.-Ing.
Lehrstuhl für Werkstoffwissenschaften (Werkstoffkunde und Technologie der Metalle)


Zitierweisen

APA:
Eibisch, H., Lohmüller, A., Kömpel, N., & Singer, R. (2008). Effect of solidification microstructure and Ca additions on creep strength of magnesium alloy AZ91 processed by Thixomolding. International Journal of Materials Research, 99(1), 56-66. https://dx.doi.org/10.3139/146.101604

MLA:
Eibisch, Harald, et al. "Effect of solidification microstructure and Ca additions on creep strength of magnesium alloy AZ91 processed by Thixomolding." International Journal of Materials Research 99.1 (2008): 56-66.

BibTeX: 

Zuletzt aktualisiert 2018-11-08 um 01:14