Graded platinum diffusion aluminide coating

摘要

A method of forming a platinum graded modified diffusion aluminide coating (100) on a nickel superalloy substrate, comprising
depositing a layer comprising platinum on the substrate, and
disposing the substrate in a sealed coating chamber (30) having a solid source comprising aluminum (53) therein disposed proximate said substrate,
controlling the aluminum activity by positioning the solid source close enough to the substrate and heating said substrate and said solid source to an elevated coating temperature to form an outwardly grown diffusion aluminide coating including an inner diffusion zone (100a) and outer, additive single phase (Ni, Pt) Al layer (100b), and wherein the outer additive layer has a concentration of between 25 to 60 weight % platinum and 20 to 35 weight % aluminum in the outer 20% of the outer additive layer and a concentration of between 10 to 25 weight % platinum and 20 to 25 weight % aluminum in the inner 20% of the outer additive layer adjacent said diffusion zone.