Structure, morphology and hydrogen desorption characteristics of amorphous and crystalline Ti-Ni alloys

Mechanical alloying and heat treatment have been used to prepare amorphous and crystalline Ti-50 at % Ni alloys. Changes of the structure, morphology and hydrogen desorption characteristics of Ti-Ni alloys were investigated. The results of X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM) show that amorphous Ti-Ni phase with uniform elemental distribution forms after 100 h of milling. A crystalline Ti-Ni alloy, consisted of Ti₂Ni phase coexisting with minor phases TiNi and TiNi₃, was formed by annealing this as-milled alloy. The amorphous Ti-Ni alloy presented good corrosion resistance, cyclic stabilization and anti-pulverization, while the crystalline one showed poor kinetic properties and severe pulverization during charge and discharge cycles.