Mechanical relaxation behavior of Zr_64.13Cu_15.75Ni_10.12Al₁₀ bulk metallic glass

The dynamic mechanical relaxation behavior of Zr_64.13Cu_15.75Ni_10.12Al₁₀ bulk metallic glass was investigated by mechanical spectroscopy. The activation energy of the main α relaxation was determined to be 4.24 eV. In order to well understand the α relaxation process, several physical and phenomenological models such as Debye model, Kohlrausch-Williams-Watt (KWW) model and quasi-point defect (QPD) model were employed to analyze the dynamic mechanical performance. It was found that Debye model was not so persuasive due to the asymmetry of the main relaxation of Zr_64.13Cu_15.75Ni_10.12Al₁₀bulk metallic glass. By contrast, KWW model agreed well with the experimental data if taking Kohlrausch parameter β_kww as 0.571. The QPD model, which had a definite physical meaning, could not only match the experimental data perfectly but also correlated the relaxation behavior with the microstructure evolution versus temperature in this bulk metallic glass.