A duplex nanocrystalline coating for high-temperature applications on single-crystal superalloy

•A duplex nanocrystalline coating is designed and prepared.•The duplex coating shows high oxidation and hot corrosion resistance.•The duplex coating displays high spallation resistance.•The duplex coating avoids element interdiffusion.

A new duplex nanocrystalline coating is designed for high temperature oxidation and hot corrosion protection. This coating combines the advantages of traditional NiCrAlY and nanocrystalline coatings, i.e., providing high resistance to oxidation and hot corrosion simultaneously, while avoids any disadvantages that the traditional coatings have suffered from, such as scale spallation, element interdiffusion (along with the formation of harmful TCP phases). It gives a good choice as the bond coating of a TBC system.