Physical mechanism of internal friction behavior of β-type bulk metallic glass composites

Phase metastability of in-situ formed β-Zr/Ti plays a vital role on mechanical properties of Zr/Ti-based bulk metallic glass composites (β-type BMGCs). In the current study, internal friction behaviors of Ti50.3Zr33.9Cu4.6Ni2.1Be9.1 BMGC containing metastable β-Ti and Ti50.3Zr27.9Cu4.6Ni2.1Be9.1Mo6 BMGC containing stable β-Ti were investigated by mechanical spectroscopy. Prior to the glass transition temperature Tg, Ti50.3Zr33.9Cu4.6Ni2.1Be9.1 BMGC exhibits pronounced internal friction ascribed to the precipitation of ω-Ti in the metastable β-Ti phase. The current investigation not only reveals the fundamental mechanism of the internal friction process of BMGCs, but also provides an effective method to characterize the metastability of β phases in β-type BMGCs.