CMAS Resistant Thermal Barrier Coating for Turbine Engines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbine engine components in desert environments experience significant degradation due to sand-related distress, where fluid sand deposits penetrate thermal barrier coatings, causing spallation and accelerated oxidation of exposed metal, leading to costly repairs.
Innovation Solution
A coating system comprising alternating layers of yttria-stabilized zirconia and a molten silicate resistant material, specifically gadolinia-stabilized zirconia, which reacts with fluid sand deposits to form a silicate oxyapatite/garnet barrier, inhibiting penetration and enhancing durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional thermal barrier coating is used, then the component provides thermal insulation, but the coating allows sand penetration leading to spallation and oxidation
Solution Approach 1:
The patent applies composite materials by creating a multi-layer coating system that combines different materials with complementary properties. The alternating layers of yttria-stabilized zirconia (providing thermal insulation) and molten silicate-resistant material (providing sand barrier properties) work together to simultaneously achieve thermal insulation and sand resistance, resolving the contradiction between coating integrity and sand penetration protection.
Solution Approach 2:
The patent converts the harmful effect of molten silicate penetration into a beneficial protective mechanism. When sand penetrates the coating, it reacts with the molten silicate-resistant material to form a solid barrier phase that actually enhances protection. This transforms the potential harm of sand contact into a beneficial self-healing barrier formation process.
2Object-affected harmful factors
If the coating is designed to resist molten silicate, then sand penetration is inhibited, but the coating structure becomes more complex
Solution Approach 1:
The patent applies segmentation by dividing the coating into multiple thin alternating layers rather than using a single thick layer. This segmented structure of alternating yttria-stabilized zirconia and molten silicate-resistant material layers provides both thermal insulation and sand resistance while maintaining a manageable and manufacturable coating structure through controlled layering.
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 sand-related distress by forming a barrier phase that prevents further penetration of molten silicate material, thereby enhancing the durability and reducing maintenance needs of turbine engine components in harsh environments.
Implementation Method 1
reacts with fluid sand deposits to form a silicate oxyapatite/garnet barrier
Implementation Method 2
forming a barrier phase that prevents further penetration of molten silicate material
Implementation Method 3
thermal barrier coating having alternating layers of yttria-stabilized zirconia and a molten silicate resistant layer
Data Source
Figure 1~2
AI summary
A turbine engine component is provided which has a substrate (14) and a thermal barrier coating (18) applied over the substrate (14). The thermal barrier coating (18) comprises alternating layers (10, 20, 22, 24) of yttria-stabilized zirconia and a molten silicate resistant material. The molten silicate resistant outer layer (24) may be formed from at least one oxide of a material selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, indium, zirconium, hafnium, and titanium or may be formed from a gadolinia-stabilized zirconia. If desired, a metallic bond coat (30) may be present between the substrate (14) and the thermal barrier coating system (18). A method for forming the thermal barrier coating system of the present invention is described.