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Physical properties of Zn‐ 22 wt.% Al‐ x wt.% Ce melt spun eutectoid alloy
Author(s) -
Ahmed E. M.
Publication year - 2012
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.201200095
Subject(s) - materials science , intermetallic , microstructure , eutectic system , alloy , nanocrystalline material , lattice constant , crystallite , metallurgy , grain size , analytical chemistry (journal) , cerium , crystallography , diffraction , chemistry , nanotechnology , physics , chromatography , optics
Zn‐ 22 wt.% Al (Zn ‐ 40 Al in atomic%) eutectoid alloys with different Cerium (Ce) contents of 0, 1, 2, and 6 (in wt.%), 0.35, 0.70 and 2.1 (in atomic%) were rapidly solidified by melt spun technique. The effects of high cooling rate and alloying element (Ce) on microstructure of the studied alloys were analyzed by X‐ray diffractometry (XRD), scanning electron microscopy (SEM) and electrical resistance measurements. The results showed that the dendrites as well as grains size were refined by the additions of Ce. The main phases in melt spun alloys were α‐Al and η‐Zn, in addition to intermetallic CeZn 5 and Al 4 Ce. Additional metastable intermetallic Al 0.71 Zn 0.29 phase has been observed only for melt spun alloy of 6 wt.% Ce content. XRD peaks of melt spun alloys demonstrated a considerable broadening with percentage of Ce due to the grain refinement and lattice distortion. Moreover, increase of Ce content results in a decrease of Al lattice constant which could be related to formation of supersaturated solid solution of Zn and/or Ce in α‐Al. Crystallite size of all phases were in the range of nanometer scale which reflects the role of the high cooling rate and the existence of Ce as alloying element for producing nanocrystalline structure. Resistance measurements of melt spun alloys show that the relative resistance rate for the alloys of higher Ce content relaxed faster to lower value than that of lower Ce content. Electrical resistance and microstructure exhibit strongly Ce content dependence.