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To refrain the interdiffusion of elements while holding good oxidation resistance,a (Ni,Pt)A1/Ni composite coating was prepared by sequential treatments of electroplating Ni and Pt and successive gaseous aluminization.In comparison with normal (Ni,Pt)Al coating,high-temperature performance of the composite coating was evaluated in isothermal oxidation test at 1100 ℃.Both the two coatings exhibited good resistance against high-temperature oxidation,but the interdiffusion of elements between composite coating and single-crystal (SC) superalloy substrate was greatly relieved,in which the thickness of secondary reaction zone (SRZ) and the amount of precipitated topologically close-packed phase in the SC alloy matrix were significantly decreased.Mechanisms responsible for delaying rate of coating degradation and SRZ growth/propagation are discussed.