Identifying the glass transitions for an Al85Ni5Y6Fe2Co2 metallic glass using a temperature modulated scanning calorimetry

An Al85Ni5Y6Fe2Co2 metallic glass was prepared by melt spinning. Two endothermic steps were observed on the normal differential scanning calorimetry, which is mostly ascribed to two glass transition processes caused by amorphous phase separation. Temperature modulated differential scanning calorimetry (TMDSC) reveals that the two endothermic steps are not attributed to two glass transition processes. High-angel annular detector dark-field scanning transmission electron microscopy (HAADF-STEM) and EDS formerly gave evidence of amorphous phase separation for the sample heated to 300oC. Only one glass transition was observed on the reversible heat flow of the TMDSC curves for this sample.