A novel parameter to describe the glass-forming ability of alloys

In this paper, we propose a new parameter for glass-forming ability (GFA) based on the combination of thermodynamic (stability of stable and metastable liquids by Delta T-m = T-m(mix) - T-l and Delta T-x = T-x - T-g, respectively) and kinetic (resistance to crystallization by T-x) aspects for glass formation. The parameter is defined as epsilon = (Delta T-m vertical bar Delta T-x vertical bar T-x)/T-m(mix) without directly adding T-g while considering the whole temperature range for glass formation up to T-m(mix), which reflects the relative position of crystallization curve in continuous cooling transformation diagram. The relationship between the e parameter and critical cooling rate (R-c) or maximum section thickness for glass formation (Z(max)) clearly confirms that the e parameter exhibits a better correlation with GFA than other commonly used GFA parameters, such as Delta T-x (=T-x - T-g), K (=[T-x - T-g]/[T-l - T-x]), Delta T*(=(T-m(mix) - T-l)/T-m(mix)), T-rg (=T-g/T-l), and gamma (=[T-x]/[T-l vertical bar T-g]). The relationship between the epsilon parameter and R-c or Z(max) is also formulated and evaluated in the study. The results suggest that the epsilon parameter can effectively predict R-c and Z(max) for various glass-forming alloys, which would permit more widespread uses of these paradigm-shifting materials in a variety of industries. (C) 2015 AIP Publishing LLC.