Wetting and interfacial phenomena between a Ni-based superalloy and silica-based ceramic cores with ZrSiO₄ additions

Abstract

Wetting behavior and interfacial reactions between a Ni-based superalloy and silica-based ceramic cores containing 10 wt.%, 30 wt.% and 50 wt.% ZrSiO4 were studied using a sessile drop method. The reaction products were characterized by SEM/EDS, EPMA and XPS analysis. SiO2 was the main component in the ceramic cores taking part in the interfacial reactions and the reaction products were composed mainly of Al2O3 layer with some ZrOx scattered. A Cr2O3 halo formed outside the wetted ceramic surface. The wetting angle increased in the initial stage to a peak value and then decreased to a constant value. The increase of the wetting angle may be attributed to the gas evaporation at the interface and the decrease of the wetting angle was due to the formation of the reaction layer at the interface.