Variable Ceramic Coating for Gas Turbine Airfoils
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Solution Overview
Problem
Current ceramic thermal barrier coatings for gas turbine airfoils lack optimal distribution of properties such as thermal conductivity, spallation resistance, and erosion resistance, leading to inadequate protection against high-temperature gas flows and foreign object impacts.
Innovation Solution
A ceramic-based coating with varying compositions and microstructures at different locations on the airfoil, primarily using yttria stabilized zirconia and gadolinia stabilized zirconia, to enhance thermal conductivity, spallation resistance, and impact resistance, with a columnar microstructure at one location and non-columnar microstructure at another, providing tailored protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a uniform ceramic thermal barrier coating is applied to the entire airfoil, then the coating provides general thermal protection, but it cannot provide optimized localized protection for different regions with different property requirements
Solution Approach 1:
The patent applies local quality by creating a ceramic-based coating where the composition and microstructure vary at different locations on the airfoil. Specifically, the coating has a first composition and microstructure at a first location and a second composition and microstructure at a second location, allowing each region to be optimized for its specific functional requirements while maintaining overall thermal protection
2Temperature
If the coating composition is optimized for thermal conductivity, then thermal management improves, but spallation resistance and erosion resistance may be compromised
Solution Approach 1:
The patent employs parameter changes by systematically varying the composition parameters (different ceramic materials such as yttria stabilized zirconia versus gadolinia stabilized zirconia) and microstructural parameters (columnar versus non-columnar) at different locations. This allows simultaneous optimization of thermal conductivity, spallation resistance, and erosion resistance across different regions of the airfoil without compromising any single property
3Ease of manufacture
If a single microstructure type is used throughout the coating, then manufacturing is simplified, but the coating cannot provide tailored performance for different operational conditions at different locations
Solution Approach 1:
The patent implements local quality by specifying that the coating has different microstructures at different locations - a first microstructure at a first location and a second microstructure at a second location. This enables tailored performance for different operational conditions while maintaining a relatively simple overall coating structure that can be applied using standard thermal spray techniques
Data Source
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AI summary
A coated article includes a substrate and a continuous ceramic-based coating supported on the substrate. The ceramic-based coating varies in at least one of composition and microstructure by location on the substrate and with respect to localized property requirements. In one example, the coated article is an article of a gas turbine engine.