The effect of initial microstructure of A356 alloys on the mechanical behavior in the semisolid state

Ning, Zhiliang and Wang, Hao and Sun, Jianfei (2006) The effect of initial microstructure of A356 alloys on the mechanical behavior in the semisolid state. Solid State Phenomena, 116-11. pp. 449-452. ISSN 1012-0394

Abstract

[Abstract]: The quality of semisolid casting largely depends on the formability of the semisolid feedstock. Despite of the semisolid casting process conditions, the initial microstructure of the feedstock plays a significant role in determining the metal formability under the semisolid state. In this study, the effect of initial microstructure of A356 alloy on the mechanical forming response in its semisolid state was investigated. A wide range of the initial microstructures varied from a very coarse dendritic structure to a fine globular structure were produced in A356 alloy using the Controlled Nucleation Method, particularly by controlling pouring temperature during solidification. Cylindrical specimens with 12 mm in diameter and 10 mm in height were compressed to a height reduction of 8 mm at constant strain rates from 1.39×10-1 /s to 1.39×10-3 /s. Strain rate jump tests were also carried out in order to evaluate the strain rate sensitivity at high fraction solid of 0.9. The materials produced with a low superheat exhibit a fine globular structure. They showed a very low compression stress in the semisolid state compared with the materials poured at high temperatures, which have coarse and dendritic structure.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Author version not held.
Depositing User: Dr Hao Wang
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - No Department
Date Deposited: 11 Oct 2007 00:59
Last Modified: 02 Jul 2013 22:42
Uncontrolled Keywords: pouring temperature, initial microstructure, strain-stress
Fields of Research (FOR2008): 09 Engineering > 0912 Materials Engineering > 091207 Metals and Alloy Materials
URI: http://eprints.usq.edu.au/id/eprint/2212

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