Internal friction of metallic glass measured as function of strain amplitude at various temperatures

The internal friction Q−1of a Zr–Ti–Cu–Ni–Be metallic glass was measured using the dynamical mechanical analyzer. The dependence of Q−1 on the strain amplitude of vibration A was investigated in the range of A = 10−5 to 10−4 at the frequency of f = 1 Hz of the bending mode vibration at various temperatures in the range of T = 300–800 K. Q−1 was almost amplitude independent, and was much enhanced near the glass transition temperature Tg (∼620 K). Fluctuations were seen in Q−1 vs A, which were very severe near Tg. The enhancement and the severe fluctuations of Q−1 near Tg were diminished after the glass was heated above the crystallization temperature Tx (∼713 K). These results were discussed on the basis of static-hysteresis type mechanical loss due to vibration of movable elements near quasi-equilibrium states in glasses.