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.