A new Pr-based bulk metallic glass and its properties

Zhang

Sci. China Ser. G-Phys. Mech. As

et al. 2008

Pr 60 Ni 25 Al 15 bulk metallic glass in a cuboid form with dimensions of 2 mm × 2 mm × 55 mm by copper mold casting method was cast. The dynamic viscosity near the glass transition region for Pr 60 Ni 25 Al 15 was measured by three-point beam bending methods. The fragility parameter m and activation energy for viscous flow of the liquid sample were calculated to be: m = 31.66, E = 10689.17 K, respectively. It was shown that the supercooled liquid of Pr 60 Ni 25 Al 15 alloy behaved much closer to strong glasses. The variation of active energy with temperature in supercooled liquid was analyzed. It was found that Kivelson's super-Arrhenius equation is not suitable for description of the activation energy in a supercooled region of Bulk metallic glass, and there is a direct proportion between activation energy crystallization and activation energy of viscous flow. bulk metallic glass, viscosity, fragility, activation energy for viscous flow, activation energy of crystallization

Viscosity properties and strong liquid behavior of Pr60Ni25Al15 bulk metallic glass-forming liquids

Zhang

Sci. China Ser. G-Phys. Mech. As

et al. 2008

New criterion in predicting glass forming ability of various glass-forming systems

Huang

2008

Chinese Phys. B

It has been confirmed that glass-forming ability (GFA) of supercooled liquids is related to not only liquid phase stability but also the crystallization resistance. In this paper, it is found that the liquid region interval (Tl – Tg) characterized by the normalized parameter of Tg/Tl could reflect the stability of glass-forming liquids at the equilibrium state, whilst the normalization of supercooled liquid region ΔTx=(Tx – Tg), i.e. ΔTx/Tx (wherein Tl is the liquidus temperature, Tg the glass transition temperature, and Tx the onset crystallization temperature) could indicate the crystallization resistance during glass formation. Thus, a new parameter, defined as ξ = Tg/Tl+ΔTx/Tx is established to predict the GFA of supercooled liquids. In comparison with other commonly used criteria, this parameter demonstrates a better statistical correlation with the GFA for various glass-forming systems including metallic glasses, oxide glasses and cryoprotectants.

Solving the initial condition of the string relaxation equation of the string model for glass transition: part-I

et al. 2010