General Electric Company

Jeffrey Arnold Fehrenbach

Gilbert Farmer

William Lee Imhoff

John Howard Starkweather

David Allen Kastrup

Michael Beverley

Raymond William Heidorn

Thomas John Tomlinson

Myron Edward Rutherford

A process of removing deposits from through-holes in a component, such as metallic bond coat and ceramic materials from cooling holes in an air-cooled gas turbine engine. The process is particularly effective in removing a TBC material deposited in a cooling hole of a component as a result of depositing a coating of the TBC material on a surface of the component, in which the deposit is removed from the cooling hole without damaging the cooling hole or the TBC coating surrounding the cooling hole on the coated surface of the component. A preferred feature is that the cooling hole, including the entrance to the hole at a surface of the component opposite the coated surface and the coating surrounding the exit of the hole at the coated surface, exhibits improved surface characteristics that increase the discharge coefficient of the cooling hole, as evidenced by an increase in the effective area of the cooling hole.

Coated component with through-hole having improved surface finish

A method of stripping coating from a portion of a coated surface of a component. The method includes fastening a mask sheet to the component over a region adjacent the portion of the coated surface. The mask sheet has a contour generally corresponding to a contour of the surface of the component. A high pressure fluid jet is sprayed from a spray head toward the portion of the coated surface after the mask sheet is fastened to the component to strip the coating from the portion of the surface. After the coating is stripped from the portion of the surface, the mask sheet is removed from the component.

Apparatus for stripping coating

Process of removing a coating deposit from a through-hole in a component and component processed thereby

A method of applying a thermal barrier coating system to a metal piece having cooling holes angled in a first direction and cooling holes angled in a second direction. The method includes spraying a bond coat on a first surface of the piece at angles with respect to the first and second directions and to a thickness selected in combination with the angles to prevent the bond coat from entirely filling any of the holes. A thermal barrier coating is sprayed on the bond coat at angles with respect to the first and second directions and to a thickness selected in combination with the angles to prevent the thermal barrier coating from entirely filling any of the holes. The method also includes spraying a high pressure fluid jet from a nozzle assembly through each hole generally parallel to the respective cooling hole.

Method for thermal barrier coating and a liner made using said method

Method and apparatus for stripping coating

A cooling hole configuration for an air-cooled component, such as a gas turbine engine airfoil. The cooling hole is configured to have cross-sectional variations and a noncircular-shaped diffuser-type opening that significantly improve the cooling film distribution across the external surface of an airfoil, with the result that heat transfer from the surrounding environment to the airfoil is reduced. The cooling hole is configured to have its central axis at an acute angle to the exterior surface of the airfoil, and defines a noncircular-shaped opening at the airfoil surface. The cooling hole generally has a first region adjacent the airfoil surface and a second region interior to the airfoil. The cooling hole is configured such that the second region has an oblong or oval-shaped cross-section, with a major diameter approximately equal to the major diameter of the first region and a minor diameter less than the major diameter of the first region, with a smooth transition existing between the first and second regions. The oblong shape of the second region is preferably the result of a recess being present in the wall of the cooling hole opposite the direction in which the cooling hole extends toward the airfoil surface, causing the central axis of the cooling hole to have an arcuate shape in which the central axis is disposed at a lesser angle to the airfoil surface in the first region than the angle in the second region. The cooling hole can be generated using a water jet technique.

Shaped cooling hole for an airfoil

A method of forming a shaped hole in a substrate, including substrates protected by coatings, as is the case where an air-cooled component has a thermal barrier coating for protection from a hostile thermal environment, such as the turbine, combustor and augmentor sections of a gas turbine engine. In particular, cooling holes are formed in an air-cooled component after a ceramic layer has been deposited on the surface of the component without damaging or spalling the ceramic layer. Processing steps generally include forming a hole through the ceramic layer and a substrate protected by the ceramic layer, thereby defining an opening at the surface of the ceramic layer. The diameter of the hole is less than the final size required for the cooling hole. A high-pressure abrasive fluid stream is then directed into the hole to enlarge the cross-section of the hole and impart a noncircular shape to the opening by removing portions of the substrate and ceramic layer without removing the ceramic layer surrounding the resulting noncircular-shaped opening. In a preferred embodiment, the abrasive fluid stream is traversed across the surface of the ceramic through a series of nested patterns that are not concentric with the central axis of the hole. Preferably, the hole acquires the desired noncircular shape in the ceramic layer, but retains a circular shape in the substrate.

Growing community of inventors

Cincinnati, OH, United States of America

Jeffrey Arnold Fehrenbach