Effect of Al2O3 addition on the wetting behavior at the interface between 3.5 WT.% MgO-PSZ crucibles and nickel melt

Abstract

This study investigates the effect of adding different Al2O3 contents (0-1.0wt.%) to 3.5wt.% MgO-PSZ ceramics on microstructure, interface wettability, and oxygen content in nickel melts. Results show that increasing Al2O3 promotes the formation of magnesium aluminate spinel (MgAl2O4) and induces a phase transition of ZrO2 from tetragonal to monoclinic. When Al2O3 exceeds 0.8wt.%, the monoclinic phase accounts for over 99%. Meanwhile, Al2O3 addition lowers the wettability between the crucible and the nickel melt, reducing adhesion and elemental diffusion. Consequently, the oxygen content in the nickel melt decreases from 45.55ppm to 32.56ppm. These findings indicate that Al2O3 effectively inhibits crucible dissolution and minimizes oxygen pickup, offering a promising strategy for developing high-stability, low-oxygen-release refractory materials to produce high-purity nickel-based alloys.