Temperature, frequency, and amplitude dependence of internal friction of metallic glass

The internal friction Q−1 and Young’s modulus E of Zr–Ti–Cu–Ni–Be bulk metallic glass specimens were measured using a dynamical mechanical spectrometer. Temperature dependence measurements were carried out for differently heat-treated specimens from room temperature up to a temperature above the crystallization temperature using several vibration frequencies (0.2–25 Hz). Two types of Q−1 peaks appeared: a high-temperature peak in the supercooled region, and a medium-temperature peak in the glassy state region. Both of them were shown to be Arrhenius-type anelastic peaks. From the obtained results, the kinetics of movable atoms in the material were discussed. The amplitude dependence of the internal friction was measured at a given frequency at various temperatures. Fluctuations and rapid changes were observed in Q−1 when the amplitude was gradually increased. The fluctuations were especially large near the glass transition temperature. The results were considered on the basis of the dynamics of the atoms in glass-forming materials near the glass transition.