Organic Matrix Composite Thermal Barrier Coating Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current thermal barrier coatings for organic matrix composites in aerospace turbine engines face challenges in adhesion due to unique surface features and material attributes, leading to poor bonding and limited high-temperature performance.
Innovation Solution
A process involving a substrate of organic matrix composite with a silica-based glass fabric roughness layer and a bonding layer composed of 80% aluminum and 20% silicon, applied with a thermal barrier coating, enhances adhesion and durability by modifying the surface without damaging the carbon fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasma sprayed thermal barrier coatings are applied directly to carbon fiber based organic matrix composite, then thermal protection is provided, but adhesion is poor due to surface features and material attributes
Solution Approach 1:
The patent introduces an intermediate layer comprising silane-modified epoxy resin and silica powder between the carbon fiber substrate and the thermal barrier coating. This intermediate layer acts as a mediator that chemically bonds to both the carbon fiber surface and the ceramic coating, resolving the adhesion problem caused by the non-polar nature of carbon fibers and the poor bonding characteristics of plasma sprayed coatings on OMC surfaces.
Solution Approach 2:
The patent modifies the surface energy and chemical properties of the substrate by applying a silane-modified epoxy resin coating. The silane modification changes the chemical parameters of the resin, enabling it to form strong bonds with both the carbon fiber substrate and the ceramic thermal barrier coating, thereby transforming the poor adhesion situation into effective bonding.
2Reliability
If surface preparation is performed to improve coating adhesion, then bond performance is enhanced, but carbon fiber damage occurs leading to degraded capability
Solution Approach 1:
The patent applies the intermediate silane-modified epoxy resin layer as a preliminary protective action before coating application. This preliminary layer protects the carbon fiber surface from mechanical damage during subsequent coating processes while simultaneously providing the necessary surface chemistry for strong bonding, thus achieving both protection and adhesion enhancement.
3Reliability
If conventional surface modification techniques are used to increase surface energy, then coating interactions are improved, but cost and complexity increase
Solution Approach 1:
The patent uses a composite intermediate layer combining silane-modified epoxy resin with silica powder. This composite material provides both the necessary surface energy for bonding and structural integrity, achieving effective surface modification through a single applied layer rather than multiple complex processing steps, thereby reducing overall process complexity.
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 achieves excellent adhesion and durability, as demonstrated by long-duration high-temperature cyclic exposure tests, effectively protecting the composite from high-temperature environments.
Implementation Method 1
A bonding layer is applied to the roughness layer
Implementation Method 2
low thermal conductivity materials are coated on the surface of the part to create a thermal gradient between the high temperature environment and the part
Implementation Method 3
advanced ceramic thermal barrier coatings
Data Source
Figure 1
AI summary
A modified organic matrix composite having a thermal barrier coating comprising a substrate comprising an organic matrix composite; a roughness layer coupled to the substrate; a bonding layer coupled to the roughness layer opposite the substrate; and a thermal barrier coating coupled to the bonding layer opposite the roughness layer.