CMC Turbine Airfoil with Reaction Barrier Coating
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Solution Overview
Problem
Known gas turbine rotor blade assemblies face issues with thermal stress and oxidation due to high temperatures, leading to reduced lifespan and increased maintenance costs.
Innovation Solution
A turbine airfoil component assembly featuring a ceramic matrix composite (CMC) airfoil with a metal alloy attachment assembly and a reaction barrier coating positioned between the CMC and metal alloy to prevent chemical reactions and reduce thermal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a metal alloy attachment assembly is used to hold the airfoil, then structural strength and ease of manufacturing are improved, but thermal stress and oxidation resistance deteriorate due to high temperature exposure
Solution Approach 1:
The patent employs a composite structure combining a metal alloy attachment assembly with a ceramic matrix composite (CMC) airfoil assembly. The CMC material is specifically selected for its high-temperature resistance and oxidation protection, while the metal alloy provides structural strength and ease of manufacturing. This composite approach allows each material to contribute its advantageous properties to the overall component performance.
Solution Approach 2:
The patent introduces a reaction barrier coating as an intermediary layer positioned between the metal alloy attachment assembly and the CMC airfoil assembly. This coating prevents direct chemical interaction and harmful reactions between the dissimilar materials while allowing thermal and mechanical stress distribution, thereby protecting the CMC from degradation and maintaining structural integrity under high-temperature conditions.
2Power
If the airfoil is exposed to high temperatures, then energy extraction efficiency is improved, but platform oxidation and cracking increase due to thermal gradients
Solution Approach 1:
The CMC airfoil assembly is specifically designed to withstand high-temperature environments, allowing the airfoil to operate efficiently at elevated temperatures without suffering from oxidation or cracking. The ceramic matrix composite material inherently resists thermal degradation and maintains its structural integrity and aerodynamic performance under these harsh conditions.
Solution Approach 2:
The reaction barrier coating serves as a protective intermediary layer that shields the CMC airfoil assembly from direct exposure to the harsh high-temperature combustion environment. This coating prevents oxidation and chemical reactions that would otherwise occur between the airfoil material and the hot combustion gases, thereby extending component life and maintaining performance.
3Reliability
If a reaction barrier coating is added between the CMC and metal alloy, then chemical reaction prevention is improved, but device complexity increases
Solution Approach 1:
The reaction barrier coating is applied as a thin protective layer between the metal alloy attachment assembly and the CMC airfoil assembly. This intermediate coating prevents direct chemical contact and harmful reactions between the dissimilar materials while maintaining a relatively simple assembly structure. The coating is integrated into the manufacturing process, adding minimal complexity while providing significant protection.
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
The solution reduces thermal stress, prevents brittle phase formation, and decreases maintenance costs by enhancing the durability and efficiency of turbine blade assemblies.
Implementation Method 1
A reaction barrier coating is disposed over at least a portion of the airfoil assembly. The reaction barrier coating is positioned between the attachment assembly and the airfoil assembly.
Data Source
AI summary
A turbine airfoil component assembly for use with a turbine engine including a attachment assembly having an inner surface defining a cavity. The attachment assembly includes a metal alloy substrate. An airfoil assembly is at least partially positioned within the attachment assembly and extends outwardly from the attachment assembly. The airfoil assembly includes a ceramic matrix composite (CMC) substrate. A reaction barrier coating is disposed over at least a portion of the airfoil assembly. The reaction barrier coating is positioned between the attachment assembly and the airfoil assembly.