Oxidation and hot corrosion behavior of gradient NiCoCrAlYSiB coatings deposited by a combination of arc ion plating and magnetron sputtering techniques

NiCoCrAlYSiB coating was prepared by arc ion plating and Al and Cr gradient NiCoCrAlYSiB coating by a combination of arc ion plating and magnetron sputtering. The results of EPMA show that the Al and Cr are uniformly distributed in the NiCoCrAlYSiB coating but have a graded distribution in the surface layer of the gradient coating. Compared to the bare DSM 11, both the NiCoCrAlYSiB coating and the gradient coating improved the oxidation resistance greatly. After 100 h hot corrosion, the gradient coating showed the best corrosion resistance. The oxidation and hot corrosion mechanisms were discussed.