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

The present invention provides methods for repairing components with damaged surfaces, particularly by removing and replacing portions of the coating system and applying new coatings to the repaired areas. The repaired areas can also include the use of re-entrant shaped grooves and channels for cooling the component. The methods involve removing the thermal barrier coating, replacing the bond coating, and replacing the structural coating in the damaged areas. The repaired areas can also include the use of new grooves in the substrate. The technical effects of the invention include improved repair efficiency and better cooling performance of components.

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 and non-uniform component temperature profiles.

As cooled turbine components are exposed to severe conditions during engine operation, they may crack or suffer other distress, such as burning.

Repair processes for conventionally cooled components can be time consuming and costly and would not be directly applicable to micro-channel cooled components.

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