Interfacial interaction between quasi-binary oxides (MgAl ₂O ₄ and Y ₃Al ₅O ₁₂) and liquid aluminum

The lack of compatibility between reactive melts, such as aluminum, and crucible materials is a recurrent problem in metallurgical practice. Thermodynamically stable oxides are commonly used as crucible materials. In the present work, the interaction of the quasibinary oxides (MgAl ₂O ₄ and YAG) with liquid Al was studied by the sessile drop method. In both systems, thecontact angle decreases from 120 to 40° in the 1273-1523 K temperature range. No presence of Mg in Al was detected after the interaction between MgAl ₂O ₄ and liquid Al, whereas a detectable amount of Y was dissolved in the melt following the interaction between YAG and molten Al. The differences in the interaction at the interface in the studied systems are attributed to the thermodynamic properties of the ternary Al-Mg-O and Al-Y-O systems.