Multicomponent metastable phase formed by crystallization of Ti-Ni-Cu-Sn-Zr amorphous alloy

Crystallization of the Ti₄₅Ni₂₀Cu₂₅Sn₅Zr₅ alloy has been studied by means of scanning differential calorimetry, x-ray diffraction, and conventional and high-resolution transmission electron microscopy. The first stage at about 750-800 K is related to the primary crystallization of the Ti₈Ni₃Cu₃SnZr metastable phase having Im3m body-centered-cubic structure with a lattice parameter of a = 0.3069 nm followed by precipitation of the secondary dotlike phase precipitates on its boundaries. The activation energy for the first exothermic reaction determined by Kissinger analysis was found to be 310 kJ/mol. CuTi, Ni₂TiZr, and an unknown phase are formed during long-term annealing at high (more than 850 K) temperature.