Coated substrates and methods of producing the same

Abstract

Coated substrates and methods of producing the same are provided. In an exemplary embodiment, a method of coating a substrate includes brazing a first bond coat layer to the substrate, where the substrate includes a ceramic material. A second bond coat layer is plasma sprayed overlying the first bond coat layer to form a composite bond coat with the first bond coat layer positioned between the second bond coat layer and the substrate. An environmental barrier coating layer is applied overlying the second bond coat layer such that the first and second bond coat layers are positioned between the substrate and the environmental barrier coating layer.

Description

[0001]This embodiment was made with Government support under contract W911W6-08-2-0001 awarded by the U.S. Army Aviation Applied Technology Directorate. The Government has certain rights in this embodiment.TECHNICAL FIELD[0002]The present disclosure generally relates to coated substrates and methods of producing the same, and more particularly relates to ceramic substrates with protective coatings and methods of producing the same.BACKGROUND[0003]Ceramic components present numerous benefits over metallic components in the high pressure module of gas turbine engines. For example, ceramics are higher temperature-capable than many nickel-based metallic components. Ceramics also possess relatively high strength at low weights as compared to conventional superalloys. The relative thermochemical and thermomechanical stability of certain ceramics at high temperatures can reduce or eliminate the need for cooling systems that may be required for comparable nickel-based superalloys, therefore...

AI Technical Summary

Benefits of technology

This patent describes methods and materials for coating ceramic substrates for use in high-temperature environments. The methods involve applying layers of bond coat and environmental barrier coating to the substrate, with the first layer of bond coat being a rough layer to ensure good adhesion to the substrate. The second layer of bond coat is a smooth layer that helps the environmental barrier coating layer grow smoothly. The resulting composite bond coat is a rough layer with a smooth surface, and the environmental barrier coating layer is smooth and continuous with the substrate. This patent aims to provide better protection and reliability for ceramic substrates in high-temperature environments.

Problems solved by technology

The hot sections of turbine engines are challenging environments that can degrade ceramic or metallic components over time.

These hot sections, especially the high pressure turbine section, can include high temperatures, rapid temperature changes, engine vibration, erosion, corrosion from fuel additives and salts, oxidation, etc.

In many cases, the EBC does not readily adhere to the ceramic substrate of the component.

In such cases, the EBC may spall off during use.

When spallation occurs, the protection afforded the substrate by the EBC is lost and the underlying ceramic component is exposed to the engine environment.

This can shorten the service life of the component, and can increase the risk of failure during service.

However, the harsh conditions within the hot sections of turbine engines can detrimentally impact the service life of a bond coat, and a failing bond coat can result in spallation of the EBC.

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