PLATINUM ALUMINIDE CVD COATING METHOD

摘要

A method of improving the oxidation resistance of a platinum modified aluminide coating formed on a nickel base superalloy substrate, comprises providing a platinum layer on the substrate, heating the substrate in a coating retort to a temperature of at least about 1000 DEG C, forming external of the coating retort a high purity coating gas comprising hydrogen and aluminum trichloride, and introducing the coating gas into the coating retort to contact the heated substrate to form an outwardly grown, single phase [(Ni,Pt)Al] platinum modified aluminide coating having reduced concentration of at least one of a substrate substitutional alloying element and a surface active tramp element selected from at least one of B, P, and S in said coating as compared to a platinum modified aluminide coating formed at a lower temperature.