Glass transition in a marginal glass-forming alloy studied by dynamic mechanical analysis

For marginal amorphous-forming alloys, the glass transition is difficult to detect using conventional differential scanning calorimetry. Since the mechanical response is more sensitive than the thermal signal when the amorphous solid transforms to the supercooled liquid, dynamic mechanical analysis (DMA) can be used to detect the glass transition temperature in marginal amorphous-forming alloys. In the present study, DMA was successfully used to measure the glass transition in Al90Tb10 metallic glass. A glass transition temperature of 443 K was estimated from the crossover region of the storage modulus, where the crossover region corresponds to the transition from an amorphous solid to a supercooled liquid. The activation energies of 63 and 221 kJ/mol for the low temperature relaxation and viscous flow were calculated using the time-temperature superposition principle. (C) 2014 AIP Publishing LLC.