Observation of β-Relaxation in Sub-T_g 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.