Characterization of flow units in metallic glass through structural relaxations

We characterize the evolution of flow units associated with the flow defects in metallic glass by monitoring the fictive temperature change of a typical metallic glass upon isothermal annealing below its glass transition temperature. The correlations between the fictive temperature T-f, enthalpy change, and the concentration of flow units have been obtained. Such correlations help in understanding the evolution process of flow units, structural feature, and structural relaxation behaviors in metallic glasses, and can rationalize effects of the cooling rate, aging, and annealing on properties and structure of metallic glasses. (C) 2013 AIP Publishing LLC.