Comparison of oxidation behavior of NiCrAlY coatings before and after surface aluminizing modification

Surface aluminizing of the coating can effectively balance its high-temperature oxidation resistance and mechanical properties, while also minimizing the rumpling in the oxide layer caused by the phase transition. In this study, NiCrAlY coatings prepared using arc ion plating were aluminized with different Al content, which was reflected by the thickness of the Al layer deposited via magnetron sputtering. The effects of the aluminizing treatment on high-temperature oxidation resistance was investigated. After 150 h of oxidation, the original coating exhibited complete failure, evident through the flaking of the oxide layer and severe internal oxidation. The aluminizing treatment delayed the formation of an Al-depletion zone within the coating, which effectively prolonged the high-temperature durability of the coatings. Moreover, the different levers of Al content also influenced the thickness of the subsequently generated oxide layer.