Observation of β-Relaxation in Sub-Tg Isothermally Annealed Al-Based Metallic Glasses

Al85Ni5Y8Co2 and Al85Ni5Y6Co2Fe2 metallic glasses are fabricated by melt spinning. A kink or a small exothermic peak is observed for both the samples isothermally annealed at sub-glass transition temperatures. Temperature modulated differential scanning calorimetry (TMDSC) data disapprove amorphous phase separation. The activation energies derived from Kissinger plots of the exothermic process on DSC curve around glass transition temperature are consistent with those of β-relaxation of metallic glasses.