Silicon-Based Patch Formulation for Gas Turbine Cavity Repair
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Solution Overview
Problem
Silicon-based ceramic materials used in high-temperature components of gas turbine engines are prone to rapid recession due to volatilization in combustion environments, and while environmental barrier coatings provide protection, they can suffer from localized spallation and pinhole defects leading to cavity formation, which reduces load-bearing capability and affects engine efficiency.
Innovation Solution
A silicon-based patch formulation comprising 25-66% solvent, 4-10% silicon-comprising binding material, and 30-65% patching material with non-actinide Group IIIA elements, such as rare earth materials, having a bimodal or trimodal particle size distribution, which is heat-treated to form an environmentally resistant patch within cavities, enhancing durability and resistance to thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If environmental barrier coatings are applied to protect silicon-based ceramic materials from volatilization, then resistance to chemical attack is improved, but localized spallation and pinhole defects occur leading to cavity formation
Solution Approach 1:
The patent applies preliminary action by proactively filling cavities before they can significantly compromise structural integrity. The repair composition is applied to cavities as they form or periodically, preventing further degradation and maintaining load-bearing capability before critical failure occurs
Solution Approach 2:
The patent uses an intermediary approach by introducing a repair composition that acts as a mediator between the damaged substrate and the protective coating. This composition fills cavities and provides a transition layer that restores structural continuity and load-bearing capability
2Strength
If cavity repair is performed to maintain structural integrity, then load-bearing capability is improved, but repair process complexity increases
Solution Approach 1:
The patent applies parameter changes by carefully controlling the composition ratios of the repair material to match the substrate properties. The molar ratio of Group IIIA elements to silicon is maintained at 0.90-1.30, and particle size distributions are optimized to ensure proper flow, packing, and bonding characteristics, simplifying the repair process while maintaining effectiveness
Solution Approach 2:
The patent uses homogeneity by formulating a repair composition that is chemically and physically similar to the original substrate material. The composition includes silicon-based particles with Group IIIA elements at controlled ratios, creating a homogeneous repair material that integrates seamlessly with the existing silicon-based ceramic substrate
3Strength
If patching material with specific composition is used to fill cavities, then adhesive strength is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies parameter changes by defining a controlled range for the molar ratio of Group IIIA elements to silicon (0.90-1.30) rather than requiring a single precise value. This range approach maintains adhesive strength while providing manufacturing flexibility and reducing precision requirements
Solution Approach 2:
The patent uses composite materials by combining silicon-based particles with Group IIIA elements in specific ratios within a binder system. This composite approach enhances adhesive strength through synergistic interactions between components while the binder provides forgiveness for minor compositional variations
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 patch formulation effectively repairs cavities, providing enhanced adhesive strength and thermal resistance, maintaining structural integrity and operational efficiency of gas turbine engines by preventing recession and maintaining airflow, even under prolonged exposure to high temperatures.
Implementation Method 1
heat treating a silicon-based patch formulation disposed within a cavity of a silicon-based substrate, the heat treating facilitating forming a silicon-based environmentally-resistant patch within the cavity
Implementation Method 2
the particles having one or more of said elements have at least a bimodal particle size distribution, wherein a particle size of a peak of a first distribution is greater than a particle size of a peak of a second distribution
Implementation Method 3
providing enhanced adhesive strength and thermal resistance, maintaining structural integrity and operational efficiency of gas turbine engines by preventing recession
Implementation Method 4
protect the silicon-based ceramic materials from volatilization processes
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 2~3
AI summary
There is set forth herein a silicon-based patch formulation comprising about 25 to 66 percent by volume of a solvent; about 4 to 10 percent by volume of a silicon-comprising binding material; and about 30 to 65 percent by volume of a patching material, the patching material comprising particles having one or more non-actinide Group IIIA elements, wherein a molar ratio of the one or more non-actinide Group IIIA elements to silicon within the patch formulation is about 0.95 to 1.25.