Microstructural evolution of body-centered cubic structure related Ti-Zr-Ni phases in non-stoichiometric Zr-based Zr-Ti-Mn-V-Ni hydride electrode alloys

摘要

Non-stoichiometric Zr-based alloys were prepared, and the corresponding electrochemical properties were characterized as hydride electrode alloys. The microstructure and chemical composition of non-stoichiometric Zr-Ti-Mn-V-Ni hydride electrode alloys were systematically investigated by x-ray Rietveld refinement, transmission electron microscopy (TEM), and energy dispersive spectroscopy under TEM observation. C14, C15 Laves phases and non-Laves phases were identified in Zr_(1-x)Ti_x(MnVNi)_(2.2) (x = 0, 0.2, 0.3, 0.4) alloys. Non-Laves phases in Zr_(1-x)Ti_x(MnVNi)_(2.2) (x = 0, 0.2, 0.3, 0.4) alloys are Ti-Zr-Ni phases related to the TiNi phase with pseudo-body-centered-cubic structure of the CsCl type. The evolution of crystallography and phase constitution for Ti-Zr-Ni non-Laves phases with different alloy composition was systematically studied. The influence of the Ti-Zr-Ni phases on the electrochemical properties of non-stoichiometric Zr_(1-x)Ti_x(MnVNi)_(2.2) alloys is briefly discussed.