Dynamic mechanical behaviors of a metastable β-type bulk metallic glass composite

Depending on the beta stability, different phase transformations may occur in beta-type titanium, resulting in various mechanical behaviors. In this paper, a metastable beta-type bulk metallic glass (BMG) composite Ti45.7Zr33Cu5.8Co3Be12.5 was investigated and analyzed using dynamic mechanical spectroscopy. During the heating below the glass transition temperature, the nano-sized omega-Ti phase is precipitated from the metastable beta-Ti dendrite which leads to an anomalous increase of storage modulus, accompanied by an exothermic event. The thermal annealing has significant influence on the structural relaxation behaviors, the time dependency on the loss factor tans can be well fitted by the proposed exponential equation, the kinetic parameter beta(KWW) reflects the degree of deviation from a single Debye relaxation and is linked to the dynamic heterogeneity in the glass. The findings provide information to better understand the complex dynamic mechanical relaxation behaviors of the metastable beta-type BMG composites. (C) 2019 Elsevier B.V. All rights reserved.