Thermodynamics and kinetics of the Mg65Cu25Y10 bulk metallic glass forming liquid
The thermodynamics and kinetics of the bulk metallic glass forming Mg65Cu25Y10 liquid were investigated using differential scanning calorimetry and three-point beam bending. The experiments lead to the determination of the thermodynamic functions as well as the viscosity of the supercooled liquid. The viscosity shows a temperature dependence, which is consistent with that of a strong glass similar to Zr–Ti–Cu–Ni–Be bulk metallic glasses or sodium silicate glasses. This contrasts with more fragile conventional metallic glass formers or pure metals. The relatively weak temperature dependence of the thermodynamic functions of the supercooled liquid is related to these sluggish kinetics in the supercooled liquid. Entropy, viscosity, and kinetic glass transition are compared in the frameworks of the fragility concept and the Adam–Gibbs theory. Strong liquid behavior retards the formation of crystals kinetically and thermodynamically.
© 1998 American Institute of Physics. (Received 8 December 1997; accepted 12 January 1998) This work was supported by the U.S. Department of Energy (Grant No. DEFG-03-86ER45242). Partial support for R. Busch was provided by the Alexander von Humboldt Foundation via the Feodor Lynen Program.
Published - BUSjap98.pdf