Oxidation of a NiCrAlYSi overlayer with or without a diffusion barrier deposited by one-step arc ion plating

Abstract: The coating systems of a NiCrAlYSi overlayer with or without a diffusion barrier (DB) were deposited by one-step arc ion plating (AIP). Isothermal and cyclic oxidations were performed at 1050°C for 100h and 100 cycles, respectively. The results indicate that the duplex coating system exhibits a more effective protection for the substrate, where thin and continuous scales are adhered to the overlayer surface, and very limited oxidation and interdiffusion attacks are detected. After exposure for 100h or 100 cycles, the DB is stable and efficient. The oxidation resistance mechanism for the two coating systems is discussed. [Copyright &y& Elsevier]