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

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−xTi_x(MnVNi)_2.2 (x = 0, 0.2, 0.3, 0.4) alloys. Non-Laves phases in Zr_1-xTi_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−xTi_x(MnVNi)_2.2 alloys is briefly discussed.