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The effect of Ca on corrosion behavior of heat‐treated Mg–Al–Zn alloy
Author(s) -
Wang Y.Q.,
Li M.Z.,
Li C.,
Li X.Y.,
Fan L.Q.,
Jia T.
Publication year - 2012
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.201005957
Subject(s) - corrosion , microstructure , alloy , materials science , intermetallic , magnesium , scanning electron microscope , metallurgy , magnesium alloy , precipitation , salt spray test , phase (matter) , nuclear chemistry , chemistry , composite material , physics , organic chemistry , meteorology
The effect of 0.5, 1.0, and 1.5 wt% Ca additions on the microstructure and corrosion resistance of the heat‐treated Mg–Al–Zn alloy was investigated. Addition of 0.5 wt% Ca did not form any new phase but suppressed the discontinuous precipitation of the β ‐Mg 17 Al 12 phase by being dissolved in both the second phase and magnesium matrix. In the materials containing higher amounts of Ca, however, metallographic investigation shows that Ca added to Mg–Al–Zn can obviously decrease the size of β ‐Mg 17 Al 12 and forms Al 4 Ca intermetallic compounds in the shape of bone‐like morphology. The corrosion tests used include constant immersion technique, and potentiodynamic polarization experiments and salt spray test. Surface examination and analytical studies were carried out using optical and scanning electron microscopy, EDX, and XRD. The results of corrosion tests show that magnesium alloy Mg–Al–Zn with 1.0 wt% Ca addition has the best corrosion resistance behavior.