Method for providing a protective coating on a metal-based substrate and related articles

摘要

An improved method for providing a protective coating on a metal-based substrate is disclosed. It involves the following steps: (a) applying a rough, oxidizable metallic bond layer over the substrate; (b) applying an intermediate layer of alumina over the metallic bond layer by chemical vapor deposition; and then (c) applying a zirconia-based thermal barrier coating over the intermediate layer by a plasma spray technique. The intermediate layer conforms to the bond layer and chemically isolates the bond layer from the thermal barrier coating. The metal-based substrate is often made from a superalloy.