Mixed alkaline‐earth effects on several mechanical and thermophysical properties of aluminate glasses and melts

Owing to heterogeneous nucleation at the melt-crucible interface, it is difficult to access the dynamic and physical properties of supercooled liquids of poor glass formers when using a conventional melting technique. To avoid the interface nucleation, we apply a containerless aerodynamic levitation laser-melting technique to measure the viscosity, density, and surface tension of a poor glass-forming system, ie, the mixed alkaline-earth aluminate melts. The temperature and composition (Ca/Sr) dependence of thermal-physical properties are investigated on both thermodynamically stable and metastable supercooled melts. In addition, the levitation laser-melting technique is used to quench the melts to glasses, and then the mixed alkaline-earth effects are investigated on Vickers micro-hardness and glass transition temperatures. By comparing the chosen silicate and aluminate series, we have identified weaker mixed alkaline-earth effects in aluminate series than those in silicate series, and this difference could be attributed to the different structural roles of alkaline-earth elements in two glass series.