Nanophase decomposition in eutectoid Zn - Al based alloy films

The structural evolution and phase transformation of the nanostructural films of an eutectoid Zn-Al based alloy were studied using X-ray diffraction, scanning electron microscopy and transmission electron microscopy techniques. By using electron beam deposition technique, the nanostructural thin films of the eutectoid Zn-Al based alloy were produced. The studies showed that the as deposited nanocrystalline phase ηn′ possessed a strongly preferred crystal orientation at (0002) crystal planes. It was the first time decomposition of the nanophase was discovered to start with clustering to form zones ( Z -zones ) and transitional phases, accompanying an eutectoid decomposition: ηn′→βeut′+T′. The mechanism of the decomposition of nanophases is discussed.