High-temperature oxidation behavior of laser-aided additively manufactured NiCrAlY coating

Abstract

In this study, NiCrAlY coatings were additively manufactured on the surface of IN738 substrate through a laser-aided additive manufacturing approach. The high-temperature oxidation behavior of freestanding coatings at 1200 °C was also investigated. The coatings were thick, dense, and well-bonded with dendritic γ/β microstructure. The results proved that the coatings were able to withstand the operating temperature of 1200 °C for up to ten cycles. After ten cycles of oxidation, the oxide scales formed on the coatings were mainly composed of α-Al2O3 and Al5Y3O12 phases; however, NiO, Cr2O3 and Ni(Cr,Al)2O4 phases were not detected.