# US 2018/0023399 A1 · Forming cooling passages in thermal barrier coated, combustion turbine superalloy components > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0023399 A1 - Document ID: US20180023399A1 - Status: Published application - Kind: A1 - Application number: 15/550,931 - Filed: 2016-02-17 - Published: 2018-01-25 - Earliest claimed: 2015-02-18 - Assignees: Siemens Aktiengesellschaft - Applicants: Siemens Aktiengesellschaft - Inventors: Gary B. Merrill; Jonathan E. Shipper, Jr.; Cora Hitchman - Web page: https://patentgrep.com/patent/US20180023399A1 ## CPC - F01D 11/122: {with erodable or abradable material (blades having cutting or grinding tips F01D5/20)} - B22C 7/02: Lost patterns - B22C 9/24: for hollow articles - B22D 25/02: by its peculiarity of shape; of works of art {(cylinders, pistons B22D15/02)} - B22D 29/001: {Removing cores} - B23H 1/00: Electrical discharge machining, i.e. removing metal with a series of rapidly recurring electrical discharges between an electrode and a workpiece in the presence of a fluid dielectric - B23K 26/382: by boring - B23P 15/02: turbine or like blades from one piece - C23C 4/02: Pretreatment of the material to be coated, e.g. for coating on selected surface areas - C23C 4/073: containing MCrAl or MCrAlY alloys, where M is nickel, cobalt or iron, with or without non-metal elements - C23C 4/18: After-treatment - C23C 28/3215: {at least one MCrAlX layer} - C23C 28/3455: {with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer} - F01D 5/14: Form or construction (selecting particular materials, measures against erosion or corrosion F01D5/28) - F01D 5/18: Hollow blades, {i.e. blades with cooling or heating channels or cavities (structure of hollow blades in general F01D5/147)}; Heating, heat-insulating or cooling means on blades - F01D 5/186: {Film cooling (F01D5/187 takes precedence)} - F01D 5/28: Selecting particular materials; {Particular measures relating thereto;} Measures against erosion or corrosion - F01D 5/288: {Protective coatings for blades} - F01D 11/08: for sealing space between rotor blade tips and stator (specially-shaped blade tips therefor F01D5/20) - F01D 11/127: {with a deformable or crushable structure, e.g. honeycomb} - F04D 29/526: {Details of the casing section radially opposing blade tips (ducts F04D29/545)} - F04D 29/685: {Inducing localised fluid recirculation in the stator-rotor interface} - F05D 2230/10: by removing material - F05D 2230/30: with deposition of material - F05D 2230/90: Coating; Surface treatment - F05D 2250/12: rectangular - F05D 2250/15: spiral - F05D 2250/182: crenellated, notched - F05D 2250/183: zigzag - F05D 2250/184: sinusoidal - F05D 2250/185: serpentine-like - F05D 2250/23: prismatic - F05D 2250/282: cubic pattern - F05D 2250/292: tapered - F05D 2250/294: grooved - F05D 2250/75: given by its similarity to a letter, e.g. T-shaped - F05D 2260/202: by film cooling - F05D 2260/22141: using fins or ribs - F05D 2300/175: Superalloys - F05D 2300/611: Coating - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - B22C: FOUNDRY MOULDING (moulding refractory materials in general B28B) - B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22) - B23H: WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL (processes for the electrolytic or electrophoretic production of coatings, electroforming, or apparatus therefor C25D; processes for the electrolytic removal of material from objects C25F; manufacturing printed circuits using precipitation techniques to apply the conductive material to form the desired conductive pattern H05K3/18) - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q) - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract Delamination of thermal barrier coatings (“TBC's”) (276) from superalloy substrates (262) of components (260) for turbine engines (80), such as engine blades (92), vanes (104, 106), or castings in transitions (85), is inhibited during subsequent cooling passage (270) formation. Partially completed cooling passages (264), which have skewed passage paths that end at a terminus (268), which is laterally offset from the passage entrance (266), are formed in the superalloy component (260) prior to application of the TBC layer(s) (276). The skewed, laterally offset path of each partially completed cooling passage (264) establishes an overhanging shield layer (269) of superalloy material that protects the TBC layer (276) during completion of the cooling passage (270). ## Claims ### Claim 1 A method for forming a cooling passage in a thermal barrier coated, superalloy component for a combustion turbine engine, the cooling passage having a passage path, including an inlet and an outlet, comprising: forming a partially completed cooling passage in a surface of a superalloy component for a combustion turbine engine, the partially completed cooling passage having an entrance formed in the surface, corresponding to a cooling passage inlet or outlet, and a skewed passage path within the superalloy component having a terminus distal and laterally offset from the entrance in the surface, and an overhanging shield layer of superalloy material interposed between the terminus and the surface proximate the entrance; applying a thermal barrier coating over the surface and the entrance; providing an ablation device for ablating thermal barrier coating and superalloy material; aligning the ablation device proximate the entrance; ablating thermal barrier coating material from the partially completed cooling passage with the ablation device, reaching the terminus; and completing the cooling passage by ablating superalloy material out of the skewed passage path along a the partially completed cooling passage from the terminus to the other of the cooling passage inlet or outlet, the overhanging shield layer of superalloy material inhibiting damage to the thermal barrier coating material proximate the entrance caused by ejection of ablated superalloy material out of the entrance. ### Claim 2 (depends on 1) The method of claim 1, wherein the skewed passage path is formed at an angle relative to the surface. ### Claim 3 (depends on 1) The method of claim 1, wherein the cooling passage defines a non-linear path. ### Claim 4 (depends on 1) The method of claim 1, wherein the partially completed cooling passage has an asymmetrical axial or radial cross section along the skewed passage path. ### Claim 5 (depends on 1) The method of claim 1, wherein the ablation device is a pulsed laser or an electric discharge machine. ### Claim 6 (depends on 5) The method of claim 5, further comprising applying a first level of ablation energy with the ablation device while ablating the thermal barrier coating material from the partially completed cooling passage, and applying a second, higher level of ablation energy with the ablation device while ablating superalloy material to complete the cooling passage. ### Claim 7 (depends on 6) The method of claim 6, wherein the first level of ablation energy is applied at a lower pulse rate than the second level of ablation energy. ### Claim 8 (depends on 6) The method of claim 6, wherein the first level of ablation energy is applied at a lower energy intensity than the second level of ablation energy. ### Claim 9 (depends on 6) The method of claim 6, wherein a total ablation energy transferred to the component during formation of the cooling passage is insufficient to induce solidification cracking in the component, or reheat cracking in the component during subsequent component heat treatment. ### Claim 10 (depends on 1) The method of claim 1, the wherein the thermal barrier coating comprises a thermally sprayed, or vapor deposited, or solution/suspension plasma sprayed thermal barrier coat that is applied directly to the surface, or that is applied over an intermediate bond coat later that was previously applied over the surface. ### Claim 11 (depends on 1) The method of claim 1, further comprising forming an engineered groove feature (EGF) in the thermal barrier coating after application of the thermal barrier coating, which circumscribes at least a portion of a periphery of the cooling passage inlet, prior to ablating the superalloy material. ### Claim 12 A method for forming a cooling passage in an investment cast, superalloy blade or vane component for a combustion turbine engine, the component having a component wall delimited by first and second wall surfaces, the cooling passage extending through the component wall between the first and second wall surfaces, comprising: forming a partially completed cooling passage in the first wall surface, the partially completed cooling passage having an entrance formed in the first wall surface, corresponding to a cooling passage inlet or outlet, and a skewed passage path within the first wall surface, having a terminus distal and laterally offset from the entrance, and an overhanging shield layer of superalloy material in the first wall that is interposed between the laterally offset passage terminus and the surface proximate the entrance; applying a thermal barrier coating over the first wall surface and the entrance; providing an ablation device for ablating thermal barrier coating and superalloy material; aligning the ablation device proximate the entrance; ablating thermal barrier coating material from the partially completed cooling passage with the ablation device, reaching the passage terminus; and completing the cooling passage by ablating superalloy material out of the skewed path, along the partially completed cooling passage path from the terminus to the other of the cooling passage inlet or outlet in a the second wall surface, the overhanging shield layer of superalloy material inhibiting damage to thermal barrier coating material proximate the entrance caused by ejection of ablated superalloy material out of the entrance. ### Claim 13 (depends on 12) The method of claim 12, wherein the component comprises an airfoil outer wall, with the first wall surface forming an outer surface, for exposure to combustion gas, and the second wall surface forming an inner surface that is in communication with cooling channels formed in the component. ### Claim 14 (depends on 12) The method of claim 12, the skewed path is formed at an angle relative to the first or second wall surface. ### Claim 15 (depends on 12) The method of claim 12, wherein the cooling passage is a non-linear path. ### Claim 16 (depends on 12) The method of claim 12, wherein the partially completed cooling passage has an asymmetrical axial or radial cross section. ### Claim 17 (depends on 12) The method of claim 12, further comprising forming the partially completed cooling passage while casting the blade. ### Claim 18 (depends on 12) The method of claim 12, wherein the ablation device comprises a pulsed laser or an electric discharge machine. ### Claim 19 (depends on 18) The method of claim 18, further comprising applying a first level of ablation energy with the ablation device while ablating thermal barrier coating material from the partially completed cooling passage, and applying a second, higher level of ablation energy with the ablation device while ablating superalloy material to complete the cooling passage. ### Claim 20 (depends on 12) The method of claim 12, wherein the thermal barrier coating comprises a thermally sprayed, or vapor deposited, or solution/suspension plasma sprayed thermal barrier coat that is applied directly to the component, or that is applied over an intermediate bond coat later that was previously applied to the component.