Thermodynamics, kinetics, and crystallization of Pt57.3Cu14.6Ni5.3P22.8 bulk metallic glass

We report on differential scanning calorimetry (DSC) studies to characterize the thermodynamics, kinetics and crystallization processes of the bulk metallic glass-forming alloy Pt57.3Cu14.6Ni5.3P22.8. The heat capacity of the alloy is measured for the crystalline, glassy and supercooled liquid phases. The heating rate dependence of the glass transition is used to calculate the kinetic fragility. Crystallization kinetics are determined under isothermal conditions and used to construct a time-temperature-transformation (TTT) diagram. The experimentally determined crystallization kinetics are fit to calculate the activation energy for crystallization. Our results suggest that Pt57.3Cu14.6M5.3P22.8 is neither a thermodynamically nor a kinetically stabilized glass former. Other contributions, including the activation energy for crystallization and the use of a flux are considered in the discussion to explain the good glass formability of this alloy. @ 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.