Turbine airfoil coating
AssigneeRtx Corporation
InventorsXuan Liu, Danielle E. Jencks, Glenn A. Cotnoir, Brian T. Hazel, Lucy Jean Raymond
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Abstract
A method for coating a metallic substrate includes applying an MCrAlY coating. Machining removes the MCrAlY coating from one or more regions of the substrate. A simultaneous aluminizing and chromizing: aluminizes an interior surface region of the substrate lacking the MCrAlY and at least a portion of a region where the MCrAlY remains; and chromizes an exterior surface region of the substrate lacking the MCrAlY and at least a different portion of the region where the first MCrAlY remains.
Claims20
A method for coating a metallic substrate, the method comprising:
- applying a first MCrAlY coating;
- machining to remove said first MCrAlY coating from one or more regions of the substrate;
- applying a mask having at least a chromium-containing chromizing portion to a combination of:
- regions of the substrate from which the first MCrAlY has been removed;
- and
- regions of the substrate on which the first MCrAlY remains but not on other regions of the substrate on which the first MCrAlY remains;
- aluminizing:
- an interior surface region of the substrate;
- and
- at least a portion of the region where the first MCrAlY remains absent the mask, wherein, during the aluminizing, the mask masks from the aluminizing but chromizes the regions to which the chromizing portion was applied;
- and
- removing the mask.
A blade having a metallic substrate with internal passageways and having:
- an attachment root having one or more inlets to the passageways;
- an airfoil through which the passageways pass;
- a platform between the root and the airfoil and having an underside surface adjacent the root and a gaspath surface adjacent the airfoil;
- a first coating along a majority of the airfoil comprising:
- one or more NiCoCrAlY layers progressively outwardly increasing in aluminum content;
- and
- one or more ceramic layers;
- a second coating along the internal passageways comprising:
- an aluminization;
- a third coating along the root comprising:
- a NiCoCr chromization;
- and
- a fourth coating (30) along the underside of the platform comprising:
- a NiCoCrAlY layer;
- and
- a NiCoCrAlY plus alpha-Cr layer.
A method for coating a metallic substrate, the method comprising:
- applying a first MCrAlY coating;
- machining the substrate after application of the first MCrAlY coating to remove said first MCrAlY coating from one or more regions of the substrate;
- and
- a step for simultaneously:
- aluminizing:
- an interior surface region of the substrate lacking the first MCrAlY;
- and
- at least a portion of a region where the first MCrAlY remains;
- and
- chromizing:
- an exterior surface region of the substrate lacking the first MCrAlY;
- and
- at least a different portion of the region where the first MCrAlY remains.
Dependencies are inferred from the claim text.