Viscosity and liquidus‐based predictor of glass‐forming ability of oxide glasses

Abstract

Glass‐forming ability (GFA) is a measure of the easiness to vitrify a given substance. Theoretically, it is possible to make a glass from any liquid provided it is quenched from its liquidus temperature with a cooling rate above a critical value Rc to avoid crystallization. However, measuring GFA is a laborious and time‐consuming task. Moreover, predicting the GFA of substances that have never been vitrified is of greater interest. Here, we propose and evaluate a new parameter that can predict the glass forming ability of oxide mixtures. We derived a mother parameter, GFA = 1/Rc ∝ [U(Tmax) × TL]−1, where U(Tmax) is the maximum crystal growth rate, and TL is the liquidus temperature, which strongly correlates with the experimental critical cooling rates of oxide glass‐formers. A simplified version derived from the mother parameter—which does not need (scarce) crystal growth rate data and only relies on viscosity η and TL, GFA ∝ [η(TL)/TL2]—also correlates well with the Rc of several oxide compositions. This new GFA parameter, dubbed Jezica, works when heterogeneous nucleation prevails. It corroborates the widespread concept that substances having high viscosity at TL, and a low TL can be easily vitrified, and provides a powerful tool for the quest and design of novel glasses.

Deep learning aided rational design of oxide glasses

“…Further, the GSCs also provide insights into the correlations of different properties, for example, a positive correlation with Young's modulus and glass transition temperature 43 , or shear modulus and hardness 44 , the atomic origin of which requires to be investigated using tailored experiments and simulations. Similarly, the ratio of Tg and liquidus temperature may provide insights to glass forming ability 45 . Thus, Fig.…”

Determining the liquidus viscosity of glass‐forming liquids through differential scanning calorimetry

“…Liquid viscosity is thus a measure of glass-forming ability, which is also correlated to glass stability. 2,3 A larger η L indicates a higher glass-forming ability. Hence, η L is a governing factor for glass fiberizing processes, 4 and it is important in the design of new industrial glass compositions.…”

Which glass stability parameters can assess the glass‐forming ability of oxide systems?

“…However, the experimental process of data acquisition at several temperatures necessary for this method is very time-consuming. Other methods, such as those reported in references [2][3][4][5][6][7][8][9][10], also have inherent difficulties, making the task of estimating Rc laborious and subjected to large uncertainties [11].…”

“…Although not a "glass stability" parameter itself, we also included in our analysis a recently proposed parameter denominated Jezica [11], (Tl)/Tl², where η(Tl) is the shear viscosity at the liquidus, Tl. This parameter depends only on properties of the equilibrium liquid instead of the characteristic temperatures determined from a previously prepared glass.…”