Decoupled versus coupled growth dynamics of an irregular eutectic alloy

SCRIPTA MATERIALIA

卷:189

Article

Mohagheghi, Samira¹  Bottin-Rousseau, Sabine²  Akamatsu, Silvere²  Serefoglu, Melis¹ 

[1] Koc Univ, Dept Mech Engn, Rumeli Feneri Yolu, TR-34450 Istanbul, Turkey

[2] Sorbonne Univ, Inst NanoSci Paris, CNRS, UMR 7588, 4 Pl Jussieu, F-75252 Paris 05, France

关键词: Irregular eutectic growth;    Directional solidification;    Eutectic solidification;    Interface dynamics;    Solidification microstructures;   

DOI  :  10.1016/j.scriptamat.2020.07.053

来源: Elsevier

【 摘 要 】

We present an experimental study of irregular growth patterns observed in real time during thinsample directional solidification of a faceted/nonfaceted eutectic alloy, namely, the transparent 2-amino-2-methyl-1,3-propanediol (AMPD)-succinonitrile (SCN) system. The body-centered cubic SCN crystals are nonfaceted, while monoclinic AMPD crystals grow as faceted needles. At low velocities (<0.3 mu ms(-1)), a decoupled growth regime is observed, during which the tip of the AMPD crystals grows ahead of the SCN-liquid interface. At intermediate velocities, an unsteady coupled-growth regime takes place, with intermittent pinning of triple SCN-AMPD-liquid junctions, and frequent noncrystallographic branching. At higher velocities (>1 mu ms(-1)), two-phase fingers form. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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