3D Morphology and Formation Process of the Icosahedral Quasicrystalline Phase in Rapidly Solidified Al-Mn Alloy

Hui-Jun Kang¹，Zhong-Lue Hu²，Xiao-Xia Gao¹，Zong-Ning Chen¹，Yi-Ping Lu¹，Jin-Chuan Jie¹，Jing-Jie Guo³

1. Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province),School of Materials Science and Engineering,Dalian University of Technology2. Department of Mechanical Engineering,Texas Tech University3. School of Materials Science and Engineering,Harbin Institute of Technology

摘 要：Three-dimensional morphology and formation process of icosahedral quasicrystal phase have been investigated in a melt-spun Al-18 Mn alloy（in wt%）.Three distinct layers corresponding to varying temperature gradient have been observed on the cross section of the ribbons.3D morphologies of cellular and dendritic icosahedral phase have been obtained through electro-etching.A model has been proposed to describe the formation process of the icosahedral phase and α-Al during the rapid solidification.The icosahedral phases are primarily precipitated from the melt into fine cellular and dendritic particles,and subsequently engulfed by the α-Al which propagates in a planar morphology.

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