A wide gap braze repair, particularly for a gas turbine engine vane or a component in the hot section of the engine. The repair is characterized by a braze filled void in a damaged area of the component, a laser shock peened surface over the repaired area of the braze filled void, and a region of deep compressive residual stresses imparted by laser shock peening (LSP) extending from the laser shock peened surface into the repair.

Laser shock peening for gas turbine engine vane repair

This invention provides methods of treatment for work products of materials such as steel, bronze, plastic, etc. and particularly welded steel bodies by pulse impact energy, preferably ultrasonic, to relax fatigue and aging and extend expectant life. The treatment may occur (a) at original production, (b) during the active life period for maintenance or (c) after failure in a repair stage. The ultrasonic treatment improves the work product strength. In welded products residual stress patterns near the weld sites are relaxed and micro-stress defects such as voids and unusual grain boundaries are reduced. The basic method steps are non-destructive in nature, inducing interior pulse compression waves with ultrasonic transducers and accessory tools impacting an external product surface with enough impulse energy to heat and temporarily plasticize the metal interior and relax stresses. The nature of the work product interior structure being treated is determined by sensing the mechanical movement at the impact surface of the work body to produce feedback frequency and phase signals responsive to input impact signals. These signals automatically conform driving pulse energy frequency and phase to the input transducers to match the mechanical resonance frequency of the working transducers and increase efficiency of energy transfer. Such feedback signals also are available for automated procedures which can improve product quality and consistency.

Ultrasonic impact methods for treatment of welded structures

A thermal barrier coating ( 18 ) having a less dense bottom layer ( 20 ) and a more dense top layer ( 22 ) with a plurality of segmentation gaps ( 28 ) formed in the top layer to provide thermal strain relief. The top layer may be at least 95% of the theoretical density in order to minimize the densification effect during long term operation, and the bottom layer may be no more than 95% of the theoretical density in order to optimize the thermal insulation and strain tolerance properties of the coating. The gaps are formed by a laser engraving process controlled to limit the size of the surface opening to no more than 50 microns in order to limit the aerodynamic impact of the gaps for combustion turbine applications. The laser engraving process is also controlled to form a generally U-shaped bottom geometry ( 54 ) in the gaps in order to minimize the stress concentration effect.

Segmented thermal barrier coating and method of manufacturing the same

Damage in a blisk airfoil is machined away to create a notch. A repair is welded in the airfoil to fill the notch. The weld repair is then machined to restore the airfoil to a substantially original, pre-damaged configuration at the repair.

Blisk weld repair

An erosion resistant protective structure for a turbine engine component comprises a shape memory alloy. The shape memory alloy includes nickel-titanium based alloys, indium-titanium based alloys, nickel-aluminum based alloys, nickel-gallium based alloys, copper based alloys, gold-cadmium based alloys, iron-platinum based alloys, iron-palladium based alloys, silver-cadmium based alloys, indium-cadmium based alloys, manganese-copper based alloys, ruthenium-niobium based alloys, ruthenium-tantalum based alloys, titanium based alloys, iron-based alloys, or combinations comprising at least one of the foregoing alloys. Also, disclosed herein are methods for forming the shape memory alloy onto turbine component.

Erosion and wear resistant protective structures for turbine engine components

A method of repairing a thermal barrier coating on an article designed for use in a hostile thermal environment, such as turbine, combustor and augmentor components of a gas turbine engine. The method is particularly suited for the repair of thermal barrier coatings composed of a metallic bond layer formed on the surface of the article, and a columnar ceramic layer overlaying the bond layer. The method entails the steps of cleaning the bond layer exposed by localized spallation, treating the bond layer so as to texture its exposed surface, and then depositing a ceramic material on the surface of the bond layer so as to form a ceramic repair layer that completely covers the bond layer. Deposition of the repair layer can be carried out such that its upper surface projects above the adjacent ceramic layer, followed by abrading the repair layer to a height substantially level with the ceramic layer.

Method for repairing a thermal barrier coating

A method of laser shock peening a gas turbine engine object continuously firing a stationary laser beam, which repeatably pulses between relatively constant periods, on a portion of the object with a low power laser beam, on the order of 3-10 joules, to vaporize material on the surface of a portion of a part made of a strong hard metal, such as a titanium alloy. Laser pulses around small laser beam spots, on the order of 1 mm in diameter, are used to vaporize material on the surface of the portion of the object with the pulses around laser beam spots formed by the laser beam on the surface and form a region having deep compressive residual stresses extending into the object from the laser shock peened surface. Flowing a curtain of water over the surface upon which the laser beam is firing while preferably moving the object until the laser shock peened surface is completely covered by laser beam spots at least once. The surface may be coated with an ablative coating such as a paint which is suitable to produce the plasma or the surface may be unpainted and the metal of the object is used to produce the plasma.

Laser shock peening using low energy laser

A method for making or repairing a gas turbine engine component includes the step of directing a pulsed ultra-violet laser beam on a location of a film cooling hole after application of a thermal barrier coating to athermally remove any coating material which may be obstructing the cooling hole without damaging the engine component or removing any of the coating from the surface of the component around the cooling hole.

Method for making or repairing a gas turbine engine component

An on the fly method of laser shock peening a gas turbine engine part by continuously moving a metallic gas turbine engine part while continuously firing a stationary laser beam, which repeatably pulses between relatively constant periods, on a portion of the part with sufficient power to vaporize material on the surface of the portion of the part with the pulses around laser beam spots formed by the laser beam on the surface and form a region having deep compressive residual stresses extending into the part from the laser shock peened surface. Flowing a curtain of water over the surface upon which the laser beam is firing while moving the part until the laser shock peened surface is completely covered by laser beam spots at least once. The surface may covered by a paint which is then the material used to produce the plasma or the surface may be unpainted and the metal of the part is used to produce the plasma. The part such a fan or compressor blade may be moved linearly to produce at least one row of overlapping circular laser beam spots having generally equally spaced apart linearly aligned center points.

Seetharamaiah Mannava

Papers

Laser shock peening for gas turbine engine vane repair

Method for repairing a thermal barrier coating

Laser shock peening using low energy laser

Method for making or repairing a gas turbine engine component

On the fly laser shock peening