Method for removing an environmental coating

摘要

A method for removing an environmental coating on an article intended for use in a hostile environment, such as turbine, combustor and augmentor components of a gas turbine engine. The method is particularly suited for the repair of diffusion aluminide coatings covered by a protective oxide scale, which may further include a thermal insulating ceramic outer layer. Processing steps generally include peening the environmental coating at a temperature below the ductile-to-brittle transition temperature of the diffusion coating, such that cracks are formed in the diffusion coating. Thereafter, the diffusion coating is subjected to an acidic solution that penetrates the cracks and interacts with the coating diffusion zone, resulting in the diffusion coating being chemically stripped from its underlying substrate.