The microstructure of hot-dip galvanized Zn-11%Al-3%Mg-0.2%Si alloy coating was studied in this
article. X-ray diffraction analysis revealed the coating is composed by Zn, Al andMgZn2 phase. Optical microscope
(OM) and scanning electron microscope (SEM) observations showed the coating is occupied by snowflake-like
dendrite, double hexagonal organization and eutectic. The coating backbone was the dendrite considered to be a
phase of hexagonal close-packed (HCP) structure judging form its morphology according to the crystal growth way
in the coating. Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) researches
on the dendrite suggested that an intermediate Zn-Al phase was formed at high temperature, then decomposed
into a type of Zn-Al granular eutectoid after cooling down to room temperature, while the eutectoid Zn and Al
had a certain crystallographic relationship. The coating solidification process and the grain crystal structure were
discussed.
YU Kang-cai1,2 (余康才), LI Jun2* (李俊), LIU Xin2 (刘昕), LI Jian-guo1 (李建国), XUE Xiao-huai1* (薛小怀)
. Microstructure of Hot-Dip Galvanized Zn-Al-Mg Alloy Coating[J]. Journal of Shanghai Jiaotong University(Science), 2012
, 17(6)
: 663
-667
.
DOI: 10.1007/s12204-012-1342-5
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