Oxide Nanoparticle Coating for Gas Turbine Disk Silicon Diffusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engine disks face challenges with thermal and mechanical stresses, requiring materials with high yield strength, tensile strength, ductility, and resistance to fatigue crack propagation, and existing coatings do not effectively prevent diffusion of silicon from ceramic or ceramic matrix composite components into alloy components, leading to potential degradation.
Innovation Solution
A coating system comprising a layer of oxide nanoparticles in an oxide matrix, where the matrix material can be silica, zirconia, alumina, or chromia, and the nanoparticles can be yttria, zirconia, or chromia, applied using sol-gel techniques to provide wear resistance, hot corrosion protection, and oxidation protection, while reducing silicon diffusion and matching the coefficient of thermal expansion with the substrate to prevent cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If existing coatings are applied to alloy components in contact with ceramic or CMC components, then wear resistance is provided, but silicon diffusion from ceramic into alloy is not prevented
Solution Approach 1:
The patent introduces an intermediate coating layer comprising oxide nanoparticles (such as alumina, zirconia, or magnesia) dispersed in an oxide matrix (such as silica-based glass). This intermediate layer acts as a diffusion barrier between the alloy component and the ceramic or CMC component, specifically preventing silicon diffusion from the ceramic into the alloy while maintaining wear resistance properties.
Solution Approach 2:
The coating system employs a composite structure combining oxide nanoparticles with an oxide matrix material. This composite formulation creates a dense, chemically resistant barrier that simultaneously provides wear resistance and blocks silicon diffusion pathways, resolving the contradiction between mechanical protection and chemical barrier functionality.
2Reliability
If coating layers are applied to prevent silicon diffusion, then reliability is improved, but coating complexity increases
Solution Approach 1:
The patent modifies the chemical composition parameters of the coating by incorporating specific oxide nanoparticles (alumina, zirconia, magnesia) into the oxide matrix. This compositional change enhances silicon diffusion resistance without requiring complex multilayer structures, maintaining manufacturing simplicity while improving reliability.
3Ease of manufacture
If thermal expansion mismatch between coating and substrate is present, then coating application is simplified, but cracking occurs under thermal stress
Solution Approach 1:
The patent selects oxide nanoparticles and matrix materials whose combined thermal expansion properties match those of the alloy substrate. This thermal expansion matching prevents differential expansion stresses during thermal cycling, eliminating coating cracking while maintaining the simplicity of the coating application process.
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 coating system effectively reduces fretting and wear, provides protection against hot corrosion and oxidation, and prevents silicon diffusion, thereby enhancing the durability and performance of gas turbine engine disks by forming a distinct phase that modifies mechanical and environmental barrier properties.
Implementation Method 1
the chemical composition of the oxide nanoparticles may be different from the chemical composition of the oxide matrix, which may result in the oxide nanoparticles forming a second, distinct phase in the first phase of the oxide matrix
Implementation Method 2
the coating may reduce or substantially prevent diffusion of silicon from the ceramic or CMC component into the alloy component
Implementation Method 3
The layer may be deposited from a sol-gel
Data Source
AI summary
In some examples, an article may include a substrate and a coating on the substrate. The substrate may include a superalloy, a ceramic, or a ceramic matrix composite. The coating may include a layer comprising a matrix material and a plurality of nanoparticles. The matrix material may include at least one of silica, zirconia, alumina, titania, or chromia, and the plurality of nanoparticles may include nanoparticles including at least one of yttria, zirconia, alumina, or chromia. In some examples, an average diameter of the nanoparticles is less than about 400 nm.