Effect of Sm additions on the microstructure and corrosion behavior of magnesium alloy AZ91

Z. Hu, R. L. Liu, S. K. Kairy, X. Li, H. Yan, N. Birbilis

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18 Citations (Scopus)

Abstract

Of the alloying additions to magnesium to date, samarium (Sm) has not been widely studied. Herein, the effect of Sm on the microstructure and corrosion of AZ91 (Mg-9Al-1Zn-0.4 Mn in wt.%) were investigated using scanning and transmission electron microscopy, electrochemical measurements, mass loss, and hydrogen collection. Results reveal preferential segregation of Sm with aluminium, leading to the formation of Al 2 Sm. Formation of Al 2 Sm in AZ91 resulted in a morphology change of β-Mg 17 Al 12 phase, from a coarse, mesh structure, to a fine short rod structure – reducing the overall β-Mg 17 Al 12 phase area fraction. Microelectrochemical tests were also employed to rationalise the corrosion observed.

Original languageEnglish
Pages (from-to)144-152
Number of pages9
JournalCorrosion Science
Volume149
DOIs
Publication statusPublished - Apr 2019

Keywords

  • Alkaline corrosion
  • Intermetallics
  • Magnesium
  • Polarisation
  • SEM
  • TEM

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