Method for applying a coating system including a heat rejection layer to a substrate surface of a component

A method for applying a coating system to a substrate surface of an aircraft engine component for preventing interdiffusion between the component surface and a protective heat rejection layer applied over the component surface when the heat rejection layer is exposed to elevated temperatures, the method comprising the steps of:

• a) providing an aircraft engine afterburner seal having at least one surface as the substrate surface;
• b) applying a first layer that includes aluminum over at least a portion of the substrate surface;
• c) heating the first layer to a first predetermined temperature for a first predetermined time period in the substantial absence of oxygen to diffuse at least a portion of the aluminum into the substrate surface and to remove volatile portions of the first layer while avoiding the formation of an alumina layer;
• d) heating the remaining portion of the aluminum layer to a second predetermined temperature for a second predetermined time period in the presence of oxygen to form a continuous, tightly adherent oxidized aluminum layer;
• and
• e) applying at least one non-ceramic smooth, tightly adherent protective heat rejection layer selected from the group consisting of tantalum, platinum, palladium and rhodium directly on the oxidized aluminum layer.