About 200 mu m-thick 32.5Ni-38.5Co-21Cr-8Al-0.5Y (wt.%) coatings were sprayed onto Hastelloy-X using a high velocity oxy-fuel spraying (HVOF) method, and were oxidized between 900 and 1100 degrees C in air to study their oxidation behavior. The coating consisted mainly of Ni3Al with some Ni. Relatively thin scales were formed on the coating, due mainly to the formation of alpha-Al2O3. Additionally, some CoCr2O4 and Al5Y3O12 formed. Beneath the oxide layer, an Al-depleted zone existed.

Keywords: oxidation; NiCoCrAlY; spraying; coating