CMAS-Reactive Thermal Barrier Coating for Turbine Protection
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Solution Overview
Problem
Thermal barrier coatings in turbine components are susceptible to damage from calcium-magnesium-aluminum-silicon-oxide (CMAS) contaminants, leading to erosion, oxidation, and premature failure due to infiltration and solidification, which reduces their strain tolerance and causes delamination and spallation, necessitating improved protection methods without compromising coating efficiency.
Innovation Solution
A thermal barrier coating with partially filled surface-connected columnar voids that incorporate a CMAS-reactive material, physically separated from the substrate by a columnar cavity with an aspect ratio greater than 3, to react with and prevent CMAS infiltration, maintaining coating integrity and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CMAS-reactive phases are pre-infiltrated into the porous structure of the thermal barrier coating, then protection against CMAS infiltration is improved, but the life and efficiency of the thermal barrier coating are reduced
Solution Approach 1:
The patent applies local quality by selectively placing CMAS-reactive material only in certain columnar voids rather than uniformly throughout the coating. This creates localized protection zones where the reactive material is positioned to intercept CMAS infiltration paths, while leaving other regions with intact thermal barrier properties, thus resolving the contradiction between protection and longevity
Solution Approach 2:
The patent introduces an intermediary approach by using a barrier layer between the thermal barrier coating and the CMAS-reactive material. This barrier layer controls the interaction between CMAS and the reactive material, allowing protection to occur while preventing the formation of harmful reaction products that would reduce coating life and efficiency
2Object-affected harmful factors
If CMAS infiltrates the porous structure of the thermal barrier coating, then the coating structure is compromised, but strain tolerance is reduced and cracks propagate causing delamination and spallation
Solution Approach 1:
The patent applies preliminary action by pre-positioning CMAS-reactive material in strategic locations within the coating structure before CMAS infiltration occurs. This allows the reactive material to intercept and neutralize CMAS at the source, preventing the infiltration damage that would otherwise lead to reduced strain tolerance, crack propagation, and coating failure
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 effectively prevents CMAS infiltration, enhances the strain tolerance of thermal barrier coatings, and extends their lifespan by forming a stable reaction product that acts as a barrier, reducing the risk of delamination and spallation, thus maintaining the thermal protection of turbine components.
Implementation Method 1
the CMAS-reactive material is physically separated from the substrate by a columnar cavity having an aspect ratio greater than 3... to react with and prevent CMAS infiltration
Data Source
AI summary
Embodiments of the present disclosure are directed to an article and methods of forming the article. The article includes a thermal barrier coating disposed on a substrate. The thermal barrier coating includes a thermal barrier material and partially filled surface-connected columnar voids. The partially filled surface-connected columnar voids are interspersed with the thermal barrier material in the thermal barrier coating. At least some of the partially filled surface-connected columnar voids include a calcium-magnesium-aluminum-silicon-oxide (CMAS)-reactive material disposed within, such that the CMAS-reactive material is physically separated from the substrate by a columnar cavity having an aspect ratio greater than 3.