Plasma-sprayed NiAl coatings in contact with soda-lime glass at temperatures >1000 °C

This study investigates the interaction between atmospheric plasma sprayed Ni Al intermetallic coatings and molten soda-lime silicate glass at temperatures >1000 °C. Focusing on wetting behavior, alumina scale formation and interfacial chemical reactions. Cross-sectional analysis revealed the formation of a continuous Al 2 O 3 scale on the surface of the coating, the thickness (2–12 μm) of which increased with thermal exposure. Elemental mapping confirmed the formation of an alumina-rich interface, and the presence of white streaks resulting from an enrichment of alumina within the glass. This indicated the scale's partial dissolution into the silicate melt. The wetting behavior of Ni Al plasma-sprayed coatings is strongly influenced by heat treatment due to its impact on surface chemistry, energy and microstructure. It was observed that the contact angle increased up to 25° from the as-sprayed condition to the annealed coating. This indicates that the coatings become markedly more non-wetting and resistant to molten glass adhesion after high-temperature exposure. While the alumina layer enhances anti-wetting performance, it remains chemically active in contact with molten glass.