Effects of Iron-Rich Intermetallics and Grain Structure on Semisolid Tensile Properties of Al-Cu 206 Cast Alloys near Solidus Temperature

Bolouri, Amir; Liu, Kun; Chen, X. Grant

Abstract

© 2016, The Minerals, Metals & Materials Society and ASM International. The effects of iron-rich intermetallics and grain size on the semisolid tensile properties of Al-Cu 206 cast alloys near the solidus were evaluated in relation to the mush microstructure. Analyses of the stress–displacement curves showed that the damage expanded faster in the mush structure dominated by plate-like β-Fe compared to the mush structure dominated by Chinese script-like α-Fe. While there was no evidence of void formation on the β-Fe intermetallics, they blocked the interdendritic liquid channels and thus hindered liquid flow and feeding during semisolid deformation. In contrast, the interdendritic liquid flows more freely within the mush structure containing α-Fe. The tensile properties of the alloy containing α-Fe are generally higher than those containing β-Fe over the crucial liquid fraction range of ~0.6 to 2.8pct, indicating that the latter alloy may be more susceptible to stress-related casting defects such as hot tearing. A comparison of the semisolid tensile properties of the alloy containing α-Fe with different grain sizes showed that the maximum stress and elongation of the alloy with finer grains were moderately higher for the liquid fractions of ~2.2 to 3.6pct. The application of semisolid tensile properties for the evaluation of the hot tearing susceptibility of experimental alloys is discussed.

• Journal Article Type: Article
• Acceptance Date: Aug 16, 2016
• Online Publication Date: Sep 6, 2016
• Publication Date: Dec 1, 2016
• Deposit Date: Sep 12, 2016
• Publicly Available Date: Sep 6, 2017
• Journal: Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
• Print ISSN: 1073-5623
• Electronic ISSN: 1543-1940
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 47
• Issue: 12
• Pages: 6466-6480
• DOI: https://doi.org/10.1007/s11661-016-3744-8
• Keywords: semisolid, tensile properties
• Public URL: https://uwe-repository.worktribe.com/output/905362
• Publisher URL: http://dx.doi.org/10.1007/s11661-016-3744-8
• Related Public URLs: http://link.springer.com/article/10.1007/s11661-016-3744-8
• Additional Information: Additional Information : The final publication is available at Springer via http://dx.doi.org/10.1007/s11661-016-3744-8
• Contract Date: Sep 12, 2016