An Atomic and Mesoscopic Study of Precipitation Kinetics in Al‐Zr‐Sc Alloys

dynamics of atoms are better understood and show strong decoupling at the microscopic scale. The macroscopic descriptions of crystal nucleation and growth have now to take into account these microscopic properties to reconcile theory and experimental data. This is especially true at large degrees of supercooling where the mobility of various cations may be very different. Indeed, our results demonstrate that the high mobility of network-modifying cations can directly affect the compositions of nucleating phases and might quantitatively explain the failure of classical theories when predicting nucleation rates. In particular, the importance of mobile network modifiers questions the use of the bulk shear viscosity of the parent melt as a scaling property for kinetic factors controlling crystal nucleation. The same may be true for crystal growth. Finally, from the standpoint of materials engineering, these studies demonstrate that it is possible to predict the composition of metastable subsolidus phases if the glass transition temperature of the parent melt is known. This in turn may offer new opportunities to design advanced composite and glass-ceramic materials.