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.

1 . A method for repairing a component having a substrate comprising an outer surface and an inner surface, wherein the inner surface defines at least one hollow, interior space, wherein the substrate defines one or more grooves, wherein each groove extends at least partially along the outer surface of the substrate, the component further comprising 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 barrier coating disposed over the bond coating, wherein the one or more grooves and the structural coating together define one or more channels for cooling the component, the repair method comprising:
 removing the thermal barrier coating;   removing the bond coating;   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, wherein the structural coating is applied without the use of a sacrificial filler, such that the structural coating is applied over open ones of the one or more grooves;   applying a bond coating over the structural coating; and   applying a thermal barrier coating over the bond coating.   
     
     
         2 . The repair method of  claim 1 , wherein each groove has a base and a top, and wherein each of the respective one or more grooves narrows at the respective top thereof, such that each groove comprises a re-entrant shaped groove. 
     
     
         3 . The repair method of  claim 2 , wherein the applied structural coating completely bridges the respective grooves, such that the applied structural coating seals the respective cooling channels. 
     
     
         4 . The repair method of  claim 2 , wherein the applied structural coating defines one or more porous gaps such that the applied structural coating does not completely bridge each of the respective grooves. 
     
     
         5 . The repair method of  claim 1 , wherein performing the repair operation comprises performing one or more of:
 locally machining a portion of at least one of the one or more grooves;   forming one or more additional grooves in the substrate; and   removing one or more grooves from the substrate.   
     
     
         6 . The repair method of  claim 1 , wherein each groove has at least one discharge end, the repair method further comprising forming a crater prior to the step of applying the structural coating, such that the crater is in fluid connection with the respective discharge end for each groove, wherein the applied structural coating does not completely bridge each of the one or more craters, such that each crater defines a film exit. 
     
     
         7 . The repair method of  claim 6 , wherein a portion of the applied structural coating is deposited in the one or more craters, the repair method further comprising removing at least some of the applied structural coating deposited in each crater to form the film hole for the respective channel. 
     
     
         8 . The repair method of  claim 1 , wherein each groove has at least one discharge end, the repair method further comprising:
 forming a run-out region adjacent to the respective discharge point for each groove, wherein the run-out region is formed prior to the step of applying the structural coating, and wherein the structural coating does not bridge the one or more run-out regions, such that each run-out region forms a film hole for the respective groove.   
     
     
         9 . The repair method of  claim 8 , wherein a portion of the applied structural coating is deposited in the one or more run-out regions, the repair method further comprising removing at least a portion of the structural coating deposited in each run-out region, such that each run-out region forms a film hole for the respective groove. 
     
     
         10 . The repair method of  claim 1 , wherein performing the repair operation comprises performing one or more of:
 repairing one or more connecting grooves that intersect at least a subset of the one or more re-entrant shaped grooves, wherein the applied structural coating does not completely bridge the connecting groove(s), such that each connecting groove at least partially defines an exit region for the respective one or more cooling channels;   repairing one or more run-out regions adjacent to a respective discharge point for each groove, wherein the structural coating does not bridge the one or more run-out regions, such that each run-out region forms a film hole for the respective groove;   repairing one or more craters, wherein each crater is in fluid connection with a respective discharge end for each groove, and wherein the applied structural coating does not completely bridge each of the one or more craters, such that each crater defines a film exit for the respective groove;   repairing one or more trenches in the component, wherein each trench at least partially defines at least one exit region (for the one or more cooling channels; and   drilling one or more film holes through the thermal barrier coating, bond coating, and structural coating to intersect the respective groove(s).   
     
     
         11 . The repair method of  claim 1 , wherein each groove has at least one discharge end, the repair method further comprising:
 forming a run-out region adjacent to the respective discharge point for each groove, wherein the run-out region is formed prior to the step of applying the structural coating, and wherein a footprint of each run-out region is narrower at the discharge point for the respective groove and wider at an opposite end of the run-out region, such that the run-out region forms a diffuser film hole.   
     
     
         12 . The repair method of  claim 1 , wherein the structural coating comprises the bond coating, such that the thermal barrier coating is disposed on the structural coating. 
     
     
         13 . The repair method of  claim 1 , wherein the structural coating and the bond coating are distinct coatings. 
     
     
         14 . A method for repairing a component having a substrate comprising an outer surface and an inner surface, wherein the inner surface defines at least one hollow, interior space, wherein one or more grooves extend at least partially along the component,
 the component further comprising 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 barrier coating disposed over the bond coating,   wherein 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, wherein each groove is formed at least partially in the inner structural coating layer,   wherein the one or more grooves and the structural coating together define one or more channels for cooling the component, the repair method comprising:
 removing the thermal barrier coating; 
 removing the bond coating; 
 removing at least a portion of the outer structural coating layer in a vicinity of a damaged portion of the inner structural coating layer; 
 performing a repair operation on the damaged portion of the inner structural coating layer; 
 applying an outer structural coating layer over any exposed portions of the inner structural coating layer; 
 applying a bond coating over the outer structural coating; and 
 applying a thermal barrier coating over the bond coating. 
   
     
     
         15 . The repair method of  claim 14 , wherein each groove has a base and a top, wherein the base of each groove is wider than the top, such that each groove comprises a re-entrant shaped groove, wherein the outer layer of the structural coating is applied without the use of a sacrificial filler, such that the outer layer of the structural coating is applied over open ones of the one or more re-entrant shaped grooves, and wherein the applied outer layer of the structural coating completely bridges the respective grooves, such that the applied outer layer of the structural coating seals the respective cooling channels. 
     
     
         16 . The repair method of  claim 14 , wherein each groove has a base and a top, wherein each of the respective one or more grooves narrows at the respective top thereof, such that each groove comprises a re-entrant shaped groove, wherein the outer layer of the structural coating is applied without the use of a sacrificial filler, such that the outer layer of the structural coating is applied over open ones of the one or more re-entrant shaped grooves, and wherein the applied outer layer of the structural coating defines one or more porous gaps such that the applied outer layer of the structural coating does not completely bridge each of the respective grooves. 
     
     
         17 . The repair method of  claim 14 , wherein the repair operation comprises performing one or more of:
 machining a portion of at least one of the one or more grooves;   forming one or more additional grooves at least partially in the inner structural coating layer; and   removing one or more grooves from the inner structural coating layer.   
     
     
         18 . A method for repairing a component having a substrate comprising an outer surface and an inner surface, wherein the inner surface defines at least one hollow, interior space, wherein the substrate defines one or more grooves, wherein each groove extends at least partially along the outer surface of the substrate, wherein each groove has a base and a top, wherein each of the respective one or more grooves narrows at the respective top thereof, such that each groove comprises a re-entrant shaped groove, the component further comprising 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 barrier coating disposed over the bond coating, wherein the one or more re-entrant shaped grooves and the structural coating together define one or more re-entrant shaped channels for cooling the component, the repair method comprising:
 removing the thermal barrier coating;   removing the bond coating;   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;   applying a bond coating over the structural coating; and   applying a thermal bather coating over the bond coating.   
     
     
         19 . The repair method of  claim 18 , wherein the entire structural coating is removed, and wherein the structural coating is applied globally over the substrate after the repair operation has been performed. 
     
     
         20 . The repair method of  claim 18 , wherein the structural coating is applied without the use of a sacrificial filler, such that the structural coating is applied over open ones of the one or more re-entrant shaped grooves. 
     
     
         21 . The repair method of  claim 18 , wherein the repair operation comprises performing one or more of:
 machining a portion of at least one of the one or more re-entrant shaped grooves;   forming one or more additional grooves in the substrate; and   removing one or more grooves from the substrate.   
     
     
         22 . The repair method of  claim 18 , wherein each groove has at least one discharge end, the repair method further comprising:
 forming a run-out region adjacent to the respective discharge point for each re-entrant shaped groove, wherein the run-out region is formed prior to the step of applying the structural coating, and wherein the applied structural coating does not bridge the one or more run-out regions, such that each run-out region forms a film hole for the respective re-entrant shaped groove.   
     
     
         23 . The repair method of  claim 18 , wherein each groove has at least one discharge end, the repair method further comprising:
 forming a run-out region adjacent to the respective discharge point for each re-entrant shaped groove, wherein the run-out region is formed prior to the step of applying the structural coating, wherein a portion of the applied structural coating is deposited in the one or more run-out regions; and   removing at least a portion of the applied structural coating deposited in each run-out region, such that each run-out region forms a film hole for the respective re-entrant shaped groove.   
     
     
         24 . The repair method of  claim 18 , wherein each re-entrant shaped groove has at least one discharge end, the repair method further comprising:
 forming a run-out region adjacent to the respective discharge point for each re-entrant shaped groove, wherein the run-out region is formed prior to the step of applying the structural coating, and wherein a footprint of each run-out region is narrower at the discharge point for the respective re-entrant shaped groove and wider at an opposite end of the run-out region, such that the run-out region forms a diffuser film hole.   
     
     
         25 . The repair method of  claim 18 , wherein each groove has at least one discharge end, the repair method further comprising forming a crater prior to the step of applying the structural coating, such that the crater is in fluid connection with the respective discharge end for each groove, wherein the applied structural coating does not completely bridge each of the one or more craters, such that each crater defines a film exit. 
     
     
         26 . The repair method of  claim 25 , wherein a portion of the applied structural coating is deposited in the one or more craters, the repair method further comprising removing at least some of the applied structural coating deposited in each crater to form the film hole for the respective channel. 
     
     
         27 . The repair method of  claim 18  further comprising repairing at least one connecting groove in the component, such that each connecting groove intersects at least a subset of the one or more re-entrant shaped grooves, wherein the connecting groove is repaired prior to the step of applying the structural coating, and wherein the applied structural coating does not completely bridge the connecting groove, such that the connecting groove at least partially defines an exit region for the respective one or more re-entrant shaped cooling channels. 
     
     
         28 . The repair method of  claim 27 , wherein each of the one or more connecting grooves is open-shaped, and wherein a portion of the applied structural coating is disposed in the exit region of respective connecting grooves, the repair method further comprising removing at least a portion of the applied structural coating disposed in each exit region. 
     
     
         29 . The repair method of  claim 18  further comprising forming at least one or more trenches in the component to at least partially define at least one exit region for the one or more cooling channels. 
     
     
         30 . The repair method of  claim 18 , wherein performing the repair operation comprises performing one or more of:
 repairing one or more connecting grooves that intersect at least a subset of the one or more re-entrant shaped grooves, wherein the applied structural coating does not completely bridge the connecting groove(s), such that each connecting groove at least partially defines an exit region for the respective one or more re-entrant shaped cooling channels;   repairing one or more run-out regions adjacent to a respective discharge point for each groove, wherein the structural coating does not bridge the one or more run-out regions, such that each run-out region forms a film hole for the respective re-entrant shaped groove;   repairing one or more craters, wherein each crater is in fluid connection with a respective discharge end for each groove, and wherein the locally applied structural coating does not completely bridge each of the one or more craters, such that each crater defines a film exit for the respective re-entrant shaped groove;   repairing one or more trenches in the component, wherein each trench at least partially defines at least one exit region for the one or more re-entrant shaped cooling channels; and   drilling one or more film holes through the thermal barrier coating, bond coating, and structural coating to intersect the respective groove(s).   
     
     
         31 . The repair method of  claim 18 , wherein the structural coating comprises the bond coating, such that the thermal barrier coating is disposed on the structural coating. 
     
     
         32 . The repair method of  claim 18 , wherein the structural coating and the bond coating are distinct coatings. 
     
     
         33 . A method for repairing a component having a substrate comprising an outer surface and an inner surface, wherein the inner surface defines at least one hollow, interior space, the component further comprising 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 barrier coating disposed over the bond coating, the repair method comprising:
 removing the thermal barrier coating;   removing the bond coating;   removing at least a portion of the structural coating in a vicinity of a damaged portion of the component;   forming one or more grooves in the substrate, wherein each groove extends at least partially along the outer surface of the substrate;   applying a structural coating at least in a vicinity of the repaired portion of the component, wherein the one or more grooves and the applied structural coating together define one or more channels for cooling the component;   applying a bond coating over the structural coating; and   applying a thermal barrier coating over the bond coating.   
     
     
         34 . The method for repairing a component of  claim 33 , further comprising performing a repair operation on the damaged portion of the component after removing at least the portion of the structural coating and prior to applying the structural coating. 
     
     
         35 . The method for repairing a component of  claim 34 , wherein each groove has a base and a top, and wherein each of the respective one or more grooves narrows at the respective top thereof, such that each groove comprises a re-entrant shaped groove.