Thermal Barrier Coating with Non-Linear Gradient

Solution Overview

Problem

Current thermal barrier coatings (TBCs) face challenges in achieving a balance between low thermal conductivity and high toughness, with materials like 8YSZ offering high toughness but high thermal conductivity, while compositions like 55YSZ lack toughness, making them unsuitable for demanding engine designs.

Innovation Solution

The development of a solution precursor plasma spray (SPPS) process that forms TBCs with non-linear compositional and porosity gradients, allowing for a unique microstructure that combines toughness through crack deflection mechanisms with high compositional flexibility, using a deposition mixture adjusted by multiple independent inputs during the spray process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If 8YSZ material is used for TBC, then toughness is improved, but thermal conductivity increases

Engineering Contradiction:

ImprovetoughnessVSAvoidthermal conductivity

Core Design Contradiction:

StrengthVSLoss of energy

Solution Approach 1:

The patent applies local quality by creating a compositional gradient where the TBC transitions from 8YSZ at the substrate interface to 55YSZ at the outer surface. This means different regions of the coating have different compositions optimized for their specific functions: the inner region provides toughness while the outer region provides low thermal conductivity, resolving the contradiction between these two properties.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining multiple YSZ compositions (8YSZ and 55YSZ) in a single graded coating structure. This composite approach allows the coating to simultaneously exhibit both high toughness (from the 8YSZ region) and low thermal conductivity (from the 55YSZ region), eliminating the need to choose one material over the other.

Inventive Principle:

Principle #40Composite materials

2Loss of energy

If 55YSZ material is used for TBC, then thermal conductivity is reduced, but toughness decreases

Engineering Contradiction:

Improvethermal conductivityVSAvoidtoughness

Core Design Contradiction:

Loss of energyVSStrength

Solution Approach 1:

The patent applies local quality by creating a compositional gradient where the TBC transitions from 8YSZ at the substrate interface to 55YSZ at the outer surface. This means different regions of the coating have different compositions optimized for their specific functions: the inner region provides toughness while the outer region provides low thermal conductivity, resolving the contradiction between these two properties.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining multiple YSZ compositions (8YSZ and 55YSZ) in a single graded coating structure. This composite approach allows the coating to simultaneously exhibit both high toughness (from the 8YSZ region) and low thermal conductivity (from the 55YSZ region), eliminating the need to choose one material over the other.

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If uniform composition is used throughout TBC, then manufacturing is simplified, but performance is compromised

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidoverall performance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies parameter changes by systematically varying the YSZ composition parameter through the thickness of the coating. The composition transitions from 8YSZ near the substrate to 55YSZ at the surface, creating an optimized gradient structure that enhances both toughness and thermal insulation performance compared to uniform compositions.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by creating a compositional gradient where the TBC transitions from 8YSZ at the substrate interface to 55YSZ at the outer surface. This means different regions of the coating have different compositions optimized for their specific functions: the inner region provides toughness while the outer region provides low thermal conductivity, resolving the contradiction between these two properties.

Inventive Principle:

Principle #3Local quality

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 resulting TBCs exhibit increased toughness and low thermal conductivity, enabling improved durability and efficiency in high-temperature environments, such as gas turbine engines, by accommodating thermal expansion strains and inhibiting crack propagation.

Implementation Method 1

spraying a deposition mixture of a first composition and a second composition via a solution precursor plasma spray apparatus onto a surface of a substrate

Methodology Applied

Scientific EffectPlasma spray: Plasma Spray

Data Source

PatentUS20240117481A1Gradient within a thermal barrier coating and methods of their formation

Publication Date: 2024.04.11 GENERAL ELECTRIC CO

AI summary

Methods are provided for forming a thermal barrier coating having a non-linear compositional gradient and/or a non-linear porosity gradient, along with coated components formed therefrom. The method includes spraying a deposition mixture of a first composition and a second composition via a solution precursor plasma spray apparatus onto a surface of a substrate; while spraying the deposition mixture, adjusting at least one deposition parameter such that the thermal barrier coating is formed with the non-linear gradient.