High-temperature corrosion behaviour of plasma sprayed lanthanum magnesium hexaluminate coating by vanadium oxide

Plasma sprayed lanthanum magnesium hexaluminate (LaMgAl11O19, LaMA) coating degraded by molten V2O5 at 710–1050 °C was studied. LaVO4, Mg0.388Al2.408O4 and γ-Al2O3 were the main corrosion products at 710 °C and 800 °C, while the corrosion products were LaVO4, MgAl2O4, α-Al2O3 at 950 °C and 1050 °C. AlVO4 as an important intermediate corrosion product had strong influences on the formations of γ- or α-Al2O3 at different temperature regions. Recrystallization and hot corrosion happened to LaMA coating simultaneously at 950 °C and 1050 °C. However, at 800 °C, LaMA coating underwent the most serious degradation along the coating thickness direction due to the presence of amorphous phase.