Formation and evolution of spherocrystals in a NiTiZrAlCuSi amorphous alloy

The microstructure of a NiTiZrAlCuSi bulk metallic glass was investigated by transmission electron microscopy (TEM) attached with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). TEM results showed that some spherocrystals were embedded in the amorphous matrix, but XRD patterns from the sample did not reveal distinct diffraction peaks from the minor amount of spherocrystals. EDS analyses indicated that the composition of these spherocrystals was similar to that of the metallic glasses matrix. To further study the evolution of these spherocrystals, isothermal crystallization experiment was carried out using differential scanning calorimetry (DSC). DSC curves and XRD patterns reveal the microstructure difference of the sample at different heating times. TEM images record the evolution processes of the metastable spherocrystal and amorphous matrix.