Study on the oxidation behavior of a novel thermal barrier coating system using the nanocrystalline coating as bonding coating on the single-crystal superalloy

A novel thermal barrier coating system with a double columnar structure was developed on a single-crystal superalloy N5 to investigate its cyclic oxidation behavior. The bond coating is a columnar nanocrystalline coating deposited by magnetron sputtering, with the same chemical composition as the superalloy N5. Compared to the NiCrAlY/YSZ thermal barrier coating, this novel system does not experience elemental interdiffusion during high-temperature exposure. Additionally, the high density of grain boundaries in the bond coating promotes the selective oxidation of Al, which significantly improves its oxidation resistance and the rumpling resistance of the thermal barrier coating.