Mechanical Relaxations of a (Zr_(77.5)Ti_(22.5))_(55)(Ni_(48)Cu_(52))_(21.25)Be_(23.75) Amorphous Alloy Studied using Dynamic Mechanical Analysis

摘要

The dynamic mechanical properties of a (Zr_(77.5)Ti_(22.5))_(55)(Ni_(48)Cu_(52))_(21.25)Be_(23.75) amorphous alloy were investigated by frequency-dependent elastic moduli and isothermal multi-frequency measurements. The frequency-dependent loss modulus showed a relaxation behavior resulting from a glass transition, and the variation of the peak frequency was related to the Arrhenius equation. Isothermal multi-frequency measurement data were used to construct the master curves of the elastic moduli and tan S by applying the time-temperature superposition principle. The temperature dependence of the shift factor was found to follow the Arrhenius relationship, and the activation energies for the low temperature relaxation and glass transition were approximately 156.6 kJ/mol and 554 kJ/mol, respectively. The glass transition temperature (T_g) was manifested by the crossover region of the shift factor dependence, and from the relationship between the shift factors and the temperature above T_g, the fragility index of this alloy was estimated.