On nanophase stability in eutectoid Zn-Al based alloy films

The structural evolution of the films of an eutectoid Zn-Al based alloy was studied using X-ray diffraction, scanning electron microscopy and transmission electron microscopy techniques. The decomposition of nanophase η′nwas discovered to have started with clustering to form Z-zones and transitional phase, which was accompanied by an eutectoid decomposition, η′n→β′eut+T′. The nanophase β′eutappeared relatively stable during prolonged ageing at 220°C. The stability of the nanophase stability is discussed by comparing it with the phase stability of the bulk microstructural alloy. The strongly preferred orientation at (111) crystal planes of the fcc nanophase β′eutconsiderably retarded the decomposition of the nanophase in the eutectoid Zn-Al based alloy films.