Thermodynamics and kinetics of the Zr41.2Ti13.8Cu10.0Ni12.5Be22.5 bulk metallic glass forming liquid: glass formation from a strong

The flow properties of Zr41.2Ti13.8Cu10.0Ni12.5Be22.5 have been measured bo th in the liquid and supercooled liquid state, spanning 15 orders of magnit ude in viscosity. We used beam bending experiments in the vicinity of the g lass transition regime and concentric cylinder rheometry near the liquidus temperature to find very large viscosities for a metallic system of 2 Pa s in the equilibrium liquid. The temperature dependence of the viscosity is d iscussed in the framework of the Adam-Gibbs entropy model as well as the fr ee volume model for viscous flow. The thermodynamic functions on the one si de and the specific volume on the other have been measured previously and a llow for a detailed comparison of the two phenomenological descriptions. (C ) 1999 Elsevier Science B.V. All rights reserved.