Hot corrosion behaviour of sputtered NiCrAlY nanocrystalline coating in molten sulfate at 900

Ni30Cr12Al0.3Y nanocrystalline coatings with mean grain size less than 100 nm were deposited on a single crystal Ni-base superalloy substrate by magnetron sputtering.By means of observation of the coating microstructure and measurement of the mass-change curves in hot corrosion,the hot corrosion behavior of the superalloy with and without Ni30Cr12Al0.3Y coatings in molten 75% Na 2 SO 4 + 25% K 2 SO 4 at 900 ℃ was investigated.The results indicate that the superalloy suffered svere hot corrosion and serious internal oxidation and internal sulfidation.The NiCrAlY coating effectively protects the superalloy from hot corrosion and improves the hot corrosion resistance of the superalloy due to the formation of a continuous and dense Al 2 O 3 film.