A crystallization study of Zr-Ni metallic glass in the range 55-71 atomic percent zirconium

The crystallization of Zr-Ni metallic glasses between 55 and 71 at. % Zr has been investigated using differential scanning calorimetry (DSC), x-ray diffraction (XRD), and transmission electron microscopy (TEM). Transformation temperatures, effective activation energies, and enthalpy changes are reported as a function of composition. Results of x-ray diffraction patterns taken at different positions on the DSC traces are presented. A high temperature DSC peak and x-ray diffraction patterns are presented as evidence for the occurrence of a previously unreported metastable phase between 57 and 63.5 at. % Zr. Micrographs of the first crystals which form as a function of composition within the range of this study show different morphologies corresponding to the two equilibrium phases (ZrNi and Zr2Ni) and the metastable phase. The possibility of phase separation around the eutectic at 63.5 at. % Zr and its relationship to the metastable phase is discussed.