Beschichtetes Substrat aus Superlegierung und Verfahren zum Beschichten eines Superlegierungssubstrates

摘要

A high rhenium-containing nickel superalloy article (10) has a multilayer coating (12) comprising a barrier coating (14) and an aluminide coating (16). The aluminide coating (16) is a corrosion and oxidation protective coating for the superalloy article (10). The barrier coating (14) comprises an alloy with a similar composition to the high rhenium-containing nickel superalloy article (10) but with less rhenium. The barrier coating (14) minimises diffusion of elements between the aluminide coating (16) and the superalloy article (10) to minimise the formation of topologically close packed phases at the interface between the superalloy article (10) and the multilayer coating (12). The barrier coating (12) preferably has some rhenium to minimise diffusion of rhenium from the superalloy article (10) to the barrier coating (14).