Ceramic Matrix Composite Interface Coating for Oxidation Resistance

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Solution Overview

Problem

Implementing ceramic matrix composites (CMCs) in gas turbine engines faces unique challenges due to high temperature resistance requirements, particularly in areas like the compressor and turbine sections, where existing materials struggle to maintain durability and oxidation resistance.

Innovation Solution

A ceramic matrix composite is developed with a multi-layer interface coating comprising carbon-based and boron-nitride based layers on ceramic fibers, along with an additional ceramic layer, enhancing durability and oxidation resistance by preventing crack propagation and oxidant penetration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single-layer interface coating is used on ceramic fibers, then the manufacturing process is simple, but the oxidation resistance and crack propagation prevention are insufficient

Engineering Contradiction:

Improveoxidation resistanceVSAvoidinterface coating structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The interface coating is divided into multiple functional layers: an inner layer (carbon-based or boron nitride) and an outer layer (boron nitride). This segmentation allows each layer to perform specific functions - the inner layer provides crack propagation prevention while the outer layer provides oxidation resistance, resolving the contradiction between reliability and manufacturing simplicity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses composite interface coatings combining carbon-based materials and boron nitride materials with different properties. The carbon-based inner layer provides mechanical reinforcement and crack resistance, while the boron nitride outer layer provides oxidation resistance, achieving superior overall performance through material composition

Inventive Principle:

Principle #40Composite materials

2Reliability

If a multi-layer interface coating is used on ceramic fibers, then the oxidation resistance and crack propagation prevention are improved, but the manufacturing complexity increases

Engineering Contradiction:

ImprovedurabilityVSAvoidcoating application process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The interface coating layers are applied to the ceramic fibers before the fibers are assembled into the final composite structure. This preliminary coating action ensures proper adhesion and prevents oxidation/crack propagation from the outset, simplifying the overall manufacturing process while maintaining durability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The carbon-based inner layer acts as an intermediary between the ceramic fiber and the boron nitride outer layer, providing a stable base for the outer layer deposition and ensuring proper thermal and mechanical transitions. This intermediary layer facilitates the manufacturing of multi-layer structures while maintaining material compatibility

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the interface coating is thin, then the manufacturing process is efficient, but the protection against oxidant penetration and crack propagation is insufficient

Engineering Contradiction:

Improveprotection effectivenessVSAvoidmanufacturing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The interface coating provides enhanced protection at the fiber-matrix interface where crack propagation and oxidation are most likely to occur. By concentrating the protective layers at this critical location rather than throughout the entire component, the invention achieves high protection effectiveness while maintaining manufacturing efficiency

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The multiple coating layers are nested concentrically around the ceramic fiber, with each layer providing a specific protective function. This nested structure maximizes the protective effect within a compact configuration, achieving thorough protection without excessive thickness that would reduce manufacturing efficiency

Inventive Principle:

Principle #7Nested doll (Nesting)

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 multi-layer interface coating significantly improves the durability and oxidation resistance of CMC materials, effectively preventing crack propagation and reducing oxidant ingress, thereby enhancing the performance and longevity of CMC components in high-temperature gas turbine engine applications.

Implementation Method 1

The interface coating includes a carbon-based layer disposed on each ceramic fiber of the plurality of ceramic fibers and a boron-nitride based layer disposed on the first carbon-based layer... effectively preventing crack propagation and oxidant penetration

Methodology Applied

Scientific EffectPhysical barrier:

Implementation Method 2

the boron-nitride based layer has an epitaxial crystal structure

Methodology Applied

Scientific EffectEpitaxial crystal structure: Epitaxy

Data Source

PatentUS12540554B2Ceramic component

Publication Date: 2026.02.03 RTX CORP

AI summary

A ceramic matrix composite includes a plurality of ceramic fibers and an interface coating disposed on the plurality of ceramic fibers. The interface coating includes a carbon-based layer disposed on each ceramic fiber of the plurality of ceramic fibers and a boron-nitride based layer disposed on the first carbon-based layer. The ceramic matrix composite also includes a ceramic matrix surrounding the plurality of ceramic fibers. A ceramic matrix composite and a method of forming a ceramic matrix composite component are also disclosed.