Ceramic Feature Layer Bonded to Thermal Barrier Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current thermal barrier coatings for gas turbine components, such as turbine blade outer air seals, are limited by sintering-induced spallation at high temperatures, restricting their durability and effectiveness, especially in next-generation turbines where temperatures exceed 2500-2800F (1371-1537 C), and the metallic substrate features are limited to 2000F (1093 C) to prevent oxidation-induced spallation.
Innovation Solution
A thermal barrier system comprising a bond coat and a ceramic feature layer with a honeycomb pattern, formed through additive manufacturing, which replaces metallic features with ceramic elements, allowing for higher temperature capability and improved substrate protection by extending the 2000F (1093 C) interface limit deeper into the coating system, and enhancing manufacturability by eliminating the need for crack propagation through additional coating thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional thermal barrier coatings are used, then they provide protection against erosion and oxidation, but they are limited to about 2500-2800F (1371-1537 C) surface temperatures due to sintering induced spallation
Solution Approach 1:
The patent changes the material composition parameter by replacing conventional ceramic materials with a glass-ceramic coating containing specific crystalline phases (mullite, cristobalite, tridymite) and glassy matrix, enabling the coating to withstand surface temperatures above 3000F (1649C) without sintering-induced spallation
Solution Approach 2:
The patent employs a composite glass-ceramic material system combining crystalline phases (mullite, cristobalite, tridymite) with a glassy matrix containing specific oxides (SiO2, Al2O3, B2O3, etc.), creating a material that resists spallation at high temperatures while maintaining thermal barrier properties
2Temperature
If GSAC coating is used to provide durability at 3000F (1649 C), then temperature resistance is improved, but the metallic substrate features are still limited to about 2000F (1093 C) to prevent oxidation induced spallation
Solution Approach 1:
The patent extracts and eliminates the metallic substrate features that caused oxidation-induced spallation in GSAC coatings, replacing them with a fully ceramic thermal barrier coating system that is inherently oxidation-resistant at temperatures above 2000F (1093C)
Solution Approach 2:
The patent changes the material composition by using a glass-ceramic coating with specific oxide compositions (SiO2, Al2O3, B2O3, etc.) that provides inherent oxidation resistance, eliminating the oxidation-induced spallation problem that limited metallic features to 2000F (1093C)
3Reliability
If higher initial coating thickness is used to account for rub interaction, then durability is improved, but surface temperature limitations are violated
Solution Approach 1:
The patent changes the temperature capability parameter by using glass-ceramic material that can withstand surface temperatures above 3000F (1649C), allowing the coating to maintain both high temperature resistance and adequate thickness (0.020-0.050 inches) to accommodate rub interaction without violating temperature limits
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 thermal barrier system achieves improved durability and temperature resistance, surpassing conventional geometrically segmented ceramic coatings by allowing higher surface temperatures and deeper substrate protection, while also simplifying the manufacturing process by reducing sensitivity to divot geometry and spray process requirements.
Implementation Method 1
a ceramic feature layer attached to said protective coating via an adhesive spray coat
Implementation Method 2
A thermal barrier system according to one disclosed non-limiting embodiment of the present disclosure includes a protective coating on a substrate
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A thermal barrier system (110) includes a protective coating (112) on a substrate (102), and a ceramic feature layer (114) attached to the protective coating (112) via an adhesive spray coat (130).