Repair methods for cooled components

Abstract

A method for repairing a component is provided, where the component has a substrate comprising an outer surface and an inner surface and defining one or more grooves. Each groove extends at least partially along the outer surface of the substrate. The component further includes a structural coating, a bond coating, and a thermal bather coating. The groove(s) and the structural coating define one or more channels for cooling the component. The repair method includes removing the thermal barrier and bond coatings, removing at least a portion of the structural coating in a vicinity of a damaged portion of the component, performing a repair operation on the damaged portion of the component, applying a structural coating at least in a vicinity of the repaired portion of the component, and applying a bond coating and a thermal barrier coating. Additional repair methods are also provided.

Description

BACKGROUND[0001]The invention relates generally to gas turbine engines, and, more specifically, to repair methods for cooled components.[0002]In a gas turbine engine, air is pressurized in a compressor and mixed with fuel in a combustor for generating hot combustion gases. Energy is extracted from the gases in a high pressure turbine (HPT), which powers the compressor, and in a low pressure turbine (LPT), which powers a fan in a turbofan aircraft engine application, or powers an external shaft for marine and industrial applications.[0003]Engine efficiency increases with temperature of combustion gases. However, the combustion gases heat the various components along their flowpath, which in turn requires cooling thereof to achieve a long engine lifetime. Typically, the hot gas path components are cooled by bleeding air from the compressor. This cooling process reduces engine efficiency, as the bled air is not used in the combustion process.[0004]Gas turbine engine cooling art is matu...

AI Technical Summary

Benefits of technology

[0009]One aspect of the present invention resides in a method for repairing a component having a substrate comprising an outer surface and an inner surface, where the inner surface defines at least one hollow, interior space. The substrate defines one or more grooves, where each groove extends at least partially along the outer surface of the substrate. The component further comprises a structural coating disposed over at least a portion of the outer surface of the substrate, a bond coating disposed over the structural coating, and a thermal bather coating disposed over the bond coating. The groove(s) and the structural coating together define one or more channels for cooling the component. The repair method includes removing the thermal bather coating, removing the bond coating, removing at least a portion of the structural coating in a vicinity of a damaged portion of the component, and performing a repair operation on the damaged portion of the component. The repair method further includes applying a structural coating at least in a vicinity of the repaired portion of the component, applying a bond coating over the structural coating, and applying a thermal bather coating over the bond coating.

[0010]Another aspect of the invention resides in a method for repairing a component having a substrate comprising an outer surface and an inner surface, where the inner surface defines at least one hollow, interior space. One or more grooves extend at least partially along the component. The component further comprises a structural coating disposed over at least a portion of the outer surface of the substrate, a bond coating disposed over the structural coating, and a thermal bather coating disposed over the bond coating. The structural coating comprises an inner structural coating layer disposed on the outer surface of the substrate and an outer structural coating layer disposed on the inner structural coating layer. Each groove is formed at least partially in the inner structural coating layer. The groove(s) and the structura

Problems solved by technology

However, the combustion gases heat the various components along their flowpath, which in turn requires cooling thereof to achieve a long engine lifetime.

This cooling process reduces engine efficiency, as the bled air is not used in the combustion process.

However, this cooling strategy typically results in comparatively low heat transfer rates an

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