Open AccessLiquid phase flow and microstructure formation during rapid solidification
Author(s) -
Jinfeng Xu,
B. Wei
Publication year - 2004
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.53.1909
Subject(s) - microstructure , materials science , melt spinning , alloy , phase (matter) , fiber , ribbon , composite material , metastability , thermodynamics , chemistry , physics , organic chemistry
The characteristics of rapid solidification and microstructure formation of Fe-50wt%Sn hypermonotectic alloy heve been investigated. The rapid solidification microstructure is composed of regular arrays of fiberlike βSn phase, αFe phase distributed in fiber interspacings, and a small amount of metallic compounds. The angle between the fiber array and ribbon surface is within the range of 0—15°. According to the heat transfer equation and NavierStokes equation under melt-spinning condition, the solidification behaviors and microstructure formation processes are analyzed theoretically. It is revealed that the liquid phase flow has a remarkable effect on the phase separation of hypermonotectic alloy. This separation behavior occurs in the bottom of the melt puddle, which is about 200μm from roller surface, where the shapes of separated L2 droplets are deformed by shear stress. The collision/stretch of the separated L2 droplets finally leads to the formation of fiberlike microstructures. Due to the high cooling rate, the peritectic transformation at elevated temperatures is suppressed, thus resulting in the existence of some metastable phase at room temperature.