Internal Aluminization of Cooling Passageways Without Surface Masking
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Solution Overview
Problem
The existing manufacturing process for gas turbine engine components with ceramic coatings is complex, challenging, and expensive due to the need for multiple coating steps, including aluminization, which can degrade certain surfaces and require masking to prevent contamination, leading to inefficiencies and increased costs.
Innovation Solution
A method involving the application of a slurry aluminide to internal cooling passageways, followed by heating and gas flow to aluminize the system, using a combination of Ar, He, and H2 gases, and optionally incorporating a bondcoat and ceramic coatings, to enhance oxidation resistance and thermal protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple coating steps including aluminization are applied to turbine blades, then oxidation resistance and thermal protection are improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent combines multiple coating functions (aluminization for oxidation resistance, TBC for thermal protection, and corrosion coatings) into a single integrated coating system applied through one vapor deposition process, eliminating the need for separate masking and multiple coating steps while achieving comprehensive protection
Solution Approach 2:
The coating system is designed to provide multiple functions simultaneously - oxidation resistance from aluminide layers, thermal barrier protection from ceramic TBC, and corrosion resistance - all applied through a single universal vapor deposition process that coats both internal and external surfaces
2Manufacturing precision
If masking is used to protect exterior surfaces during internal aluminization, then surface degradation is reduced, but manufacturing time and complexity increase
Solution Approach 1:
Instead of masking exterior surfaces to protect them from aluminization vapors, the patent inverts the approach by using vapor deposition to selectively coat only the desired internal surfaces through controlled vapor flow, allowing exterior surfaces to remain uncoated without masking
Solution Approach 2:
The patent extracts the masking step entirely from the manufacturing process by using a vapor deposition method that inherently directs coating material to internal surfaces through controlled vapor flow and condensation, eliminating the time-consuming masking and unmasking operations
3Reliability
If conventional aluminization methods are used on internal passageways, then oxidation resistance is improved, but surface contamination and degradation occur
Solution Approach 1:
The patent uses controlled inert gas flow as an intermediary to deliver aluminum vapor selectively to internal passageway surfaces, preventing direct contamination of exterior surfaces while achieving uniform aluminide coating inside the complex geometry
Solution Approach 2:
The patent changes the physical parameters of the deposition process by using vapor phase aluminum delivery with controlled temperature gradients and gas flow patterns, allowing precise control of where condensation and coating occur, thereby avoiding unwanted surface contamination
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method simplifies the coating process, reduces surface degradation, and enhances the oxidation resistance and thermal protection of internal components, improving manufacturing efficiency and reducing costs by integrating aluminization directly into the cooling passageways.
Implementation Method 1
heating the component to aluminize the cooling passageway system
Implementation Method 2
applying a slurry aluminide to the plurality of outlet passageways; heating the component to aluminize the cooling passageway system
Implementation Method 3
coupling the one or more inlets to a suction source; applying an external gas flow to the component, the suction source drawing the external gas in through the outlet passageways and out through the one or more inlet ports
Data Source
AI summary
A method for coating a component having: a metallic substrate; a ceramic coating having one or more ceramic coating layers atop the substrate; and a cooling passageway system comprising a plurality of feed passageways extending from one or more inlet ports and a plurality of outlet passageways. The outlet passageways have openings in the coating. The method involves: applying a slurry aluminide to the plurality of outlet passageways; coupling the one or more inlets to a suction source; applying an external gas flow to the component, the suction source drawing the external gas in through the outlet passageways and out through the one or more inlet ports, the external gas flow comprising at least 50% by volume combined one to all of Ar, He, and H2; and while the suction source is drawing the external gas, heating the component to aluminize the cooling passageway system.