Low-frequency high-temperature internal friction of bulk metallic glasses

Abstract

The internal friction (IF) of Johnson alloy (Zr–Ti–Cu–Ni–Be) glass prepared by a single-roller melt-spinning method was measured using an inverted torsion pendulum with the free decay method. The measurements were performed from room temperature, through the glass transition temperature T g, up to the crystallization temperature T x. The effect of isothermal annealing at a temperature about 20 K below T g was studied. By the annealing the unstable glassy state and the metastable supercooled state were transferred to more stable ones (stabilization). In a well-stabilized state, the background IF was flat at lower temperatures, increased rapidly at higher temperatures, and an IF peak appeared near T x together with another peak at a lower temperature. No IF peak was observed near T g. Qualitative discussions are presented for the experimental results, and possible use of the glass as a high damping material is briefly mentioned.