Effect of Sr Addition on the Solidification Structure in Al-6mass%Mg-3mass%Si Alloy

Abstract:

Al-Mg-Si system alloy have good strength and high ductility without heat treatment. However, the castability in this alloy is inferior to other aluminum alloy, in particular, hot-tearing is easy to occur during solidification. In our previous study, hot-tearing was not occurred in the case of 0.04%Sr addition to this alloy, because of the remarkable refinement of eutectic Mg₂Si phase. In this study, in order to clarify the mechanism of the change of the crystallized eutectic Mg₂Si morphology, the effect of Sr addition on the solidification structure in Al-6%Mg-3%Si alloy was investigated. By Sr addition to this alloy, the change of the nucleation mode from homogeneous to heterogeneous was occurred with the temperature drop at the start of eutectic reaction, and the great change of eutectic growth mode from facet to non-facet was thought to be a main reason improving of hot-tearing.

• Periodical: Materials Science Forum (Volume 879)
• Pages: 2383-2388
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.879.2383
• Online since: November 2016
• Authors: Emi Yanagihara*, Goshi Aoshima, Shota Komura, Seiji Saikawa, Susumu Ikeno
• Keywords: Al-Mg-Si, Hot-Tearing, Microstructure, Sr Addition

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