Microstructure analyses and phase-field simulation of partially divorced eutectic solidification in hypoeutectic Mg-Al Alloys

Kang, J.-H. and Park, J. and Song, K. and Oh, C.-S. and Shchyglo, O. and Steinbach, I.

Volume: Pages:
DOI: 10.1016/j.jma.2021.04.014
Published: 2021

In this study the partially divorced eutectic microstructure of α-Mg and β-Mg17Al12 was investigated by electron backscatter diffraction, transmission electron microscopy, and phase-field modeling in hypoeutectic Mg-Al alloys. The orientation relationships between the individual eutectic α grains, eutectic β phase, and primary α grains were investigated. While the amount of eutectic morphology is primarily determined by the Al content, the in-depth microstructure analyses and the phase-field simulation suggest non-interactive nucleation and growth of eutectic α phase in the β phase grown on the interdendritic primary α dendrites. Also, phase-field simulations showed a preferred nucleation sequence where the β phase nucleates first and subsequently triggers the nucleation of eutectic α phase at the moving β phase solidification front, which supports the microstructural analysis results. © 2021

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