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

Depending on the β stability, different phase transformations may occur in β-type titanium, resulting in various mechanical behaviors. In this paper, a metastable β-type bulk metallic glass (BMG) composite Ti_45.7Zr₃₃Cu_5.8Co₃Be_12.5 was investigated and analyzed using dynamic mechanical spectroscopy. During the heating below the glass transition temperature, the nano-sized ω-Ti phase is precipitated from the metastable β-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 tanδ can be well fitted by the proposed exponential equation, the kinetic parameter β_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 β-type BMG composites.