STATIC MEASUREMENTS FOR α- and β-RELAXATION BELOW T_g IN A Zr_(55)Cu_(30)Ni_5Al_(10)BMG

摘要

The static α- and β-relaxation in a Zr_(55)Cu_(30)Ni_5Al_(10)bulk metallic glass(BMG)was investigated by volume relaxation. The relaxation time τ_α for a-relaxation was well fitted by Vogel-Fulcher-Tammann(VFT)equation. The manifestation of β-relaxation in a lower temperature region was confirmed by isochronal change in electrical resistance, and its kinetics was examined by isothermal change in volume during relaxation. The kinetics was characterized by a pre-exponential factor of τ_(β,0)=1.4×10~(11)s and an activation energy of E_β=160 kJ/mol≈28.0 RT_g. The x-ray analysis with a synchrotron radiation revealed that the structural change was different from that of P-relaxation of metallic glasses with the trend of the chemical short range ordering(CSRO)process.