Environmental and Thermal Barrier Coating to Protect a Pre-Coated Substrate

A method to protect a pre-coated substrate from corrosion in a high-temperature aqueous environment, the method comprising:

• providing a pre-coated substrate having a substantially porous vapor-deposited coating, wherein the substantially porous vapor-deposited coating comprises a first coefficient of thermal expansion;
• providing at least one non-porous ceramic oxide-based layer having a second coefficient of thermal expansion substantially matching the first coefficient of thermal expansion;
• and
• applying, via a non-vapor deposition technique, the at least one non-porous ceramic oxide-based layer to the pre-coated substrate, to provide a hermetic seal limiting fluid access to the pre-coated substrate through the substantially porous vapor-deposited coating.

An apparatus having improved protection in various environments, the apparatus produced by the steps of:

• providing a pre-coated substrate having a substantially porous vapor-deposited coating, wherein the substantially porous vapor-deposited coating comprises a first coefficient of thermal expansion;
• providing at least one non-porous ceramic oxide-based layer having a second coefficient of thermal expansion substantially matching the first coefficient of thermal expansion;
• and
• applying, via a non-vapor deposition technique, the at least one non-porous ceramic oxide-based layer to the pre-coated substrate, wherein the at least one non-porous ceramic oxide-based layer infiltrates pores of the substantially porous vapor-deposited coating to provide a hermetic seal limiting fluid access to the pre-coated substrate through the substantially porous vapor-deposited coating.

A method to protect a pre-coated substrate from corrosion in a high-temperature aqueous environment, the method comprising:

• providing a pre-coated substrate having a substantially porous vapor-deposited coating, wherein the substantially porous vapor-deposited coating comprises a first coefficient of thermal expansion;
• providing at least one metal layer from a group consisting of aluminum, magnesium, zinc, manganese, copper, bronze, tin, and combinations thereof;
• and
• heating the pre-coated substrate with the top metal layer coating in order to oxidize the metal layer at higher temperature, wherein the resulting oxidized layer has a second coefficient of thermal expansion substantially matching the first coefficient of thermal expansion.