Oxidation behaviour of the alloy IC-6 and protective coatings

Abstract In this work, NiCoCrAlY coatings were deposited on a new Ni-base alloy, IC-6. The oxidation kinetic curves of alloy IC-6, K17 and NiCoCrAlY coatings on alloy IC-6 at 900–1100 °C were obtained. The results indicated that the oxide scales consisted of α-Al2O3, NiAl2O4, NiO, as well as a small amount of NiMoO4 and MoO2. These scales occurred after alloy IC-6 exposure at 900 °C for 100 h. The weight loss occurred when alloy IC-6 were exposed at 1050 and 1100 °C due to the formation of volatile MoO3. After the NiCoCrAlY coating was deposited, the scales mainly contained α-Al2O3, when the specimens were oxidized at 900 °C, and α-Al2O3and Cr2O3 at 1050 °C. The formation of α-Al2O3 and Cr2O3 scales on NiCoCrAlY coating was directly responsible for improving oxidation resistance of the alloy IC-6.