Method for forming different aluminide diffusion coatings on different surface areas of the same superalloy substrate

摘要

Method of forming different diffusion aluminide coatings on different surface regions of the same superalloy substrate involves positioning the substrate in a coating chamber having a aluminum-bearing coating gas flowing therein with a first substrate surface region enclosed in a masking enclosure having one or more coating gas entrance apertures communicating the interior of the enclosure to the coating gas in the coating chamber and with a second substrate surface region freely communicated to the coating gas in the coating chamber, and gas phase aluminizing the substrate by heating the substrate to an elevated coating temperature in the coating chamber having the coating gas therein to concurrently form an outwardly-grown diffusion aluminide coating on the first substrate surface region and to form an inwardly-grown, diffusion aluminide coating on the second substrate surface region of the same substrate.