Werkstück auf Superlegierungsbasis mit einer Gamma-Strich-Nickelaluminid-Beschichtung

摘要

An article for use in hostile thermal environments, such as a component of a gas turbine engine. The article includes a nickel-base superalloy substrate (22) that is prone to formation of a deleterious secondary reaction zone (SRZ), and an overlay coating (24) having a predominantly gamma prime-phase nickel aluminide (Ni 3 Al) composition suitable for use as an environmental coating (24), including a bond coat (24) for a thermal barrier coating (26). The coating (24) comprises a chromium-containing nickel aluminide intermetallic overlay coating (24) of predominantly the gamma prime phase, in which aluminum is present in the coating (24) in an amount approximately equal to the aluminum content of the superalloy substrate (22) so as to inhibit diffusion of aluminum from the overlay coating (24) into the superalloy substrate (22).