CMC Turbine Coating Surface Channels for CMAS Removal

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Solution Overview

Problem

Ceramic matrix composite (CMC) components in gas turbine engines are susceptible to damage from molten Calcium-Magnesium-Alumino-Silicate (CMAS) at high operating temperatures, leading to reduced component life and potential catastrophic failure.

Innovation Solution

Incorporating surface structures such as protrusions and channels on the coating of CMC components to modify the flow of molten CMAS, promoting its removal downstream and reducing accumulation on the surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional smooth coating surfaces are used, then manufacturing is simpler, but molten CMAS accumulates on the surface causing chemical and mechanical damage

Engineering Contradiction:

Improvecoating application simplicityVSAvoidCMAS accumulation and damage

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The coating is designed with a porous structure containing channels that allow molten CMAS to penetrate and drain through the coating layer, preventing accumulation on the surface. The porosity is controlled to optimize both CMAS removal and manufacturing feasibility.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The coating structure transitions from a smooth surface to one with localized porous channels at specific depths, creating different functional zones: a surface layer for protection and a porous layer for CMAS drainage, optimizing both manufacturing and performance.

Inventive Principle:

Principle #3Local quality

2Reliability

If the coating is made more porous to allow CMAS drainage, then CMAS resistance improves, but manufacturing complexity increases

Engineering Contradiction:

ImproveCMAS resistanceVSAvoidcoating structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The coating is segmented into distinct layers with different porosity levels and functions. The upper layer provides protection while the lower layer contains the porous channel structure for CMAS drainage, simplifying manufacturing by dividing the complex function into manageable segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The porous channel structure is pre-formed within the coating during the coating application process rather than requiring post-manufacturing modification, integrating the CMAS drainage function into the coating fabrication itself and reducing overall manufacturing complexity.

Inventive Principle:

Principle #10Preliminary action

3Object-affected harmful factors

If surface features are added to the coating, then CMAS flow modification improves, but manufacturing precision requirements increase

Engineering Contradiction:

ImproveCMAS flow controlVSAvoidsurface feature geometry

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The coating structure itself provides the surface features through its porous channel architecture, eliminating the need for separate precision-machined surface features. The coating fabrication process automatically creates the necessary geometry for CMAS flow modification.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The coating combines different material phases and structures to achieve both protection and CMAS flow control functions, using composite architecture rather than precision-machined features on a homogeneous coating, thereby reducing manufacturing precision requirements.

Inventive Principle:

Principle #40Composite materials

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 surface structures effectively reduce CMAS exposure in critical areas, prolonging component life by minimizing mechanical and chemical damage, and facilitating the atomization and expulsion of molten materials from high-temperature environments.

Implementation Method 1

the channels are configured to modify a flow of molten Calcia-Magnesia-Alumina Silicate (CMAS) over the outer surface of the coating in a gas flow over the outer surface of the article

Methodology Applied

Scientific EffectFluid flow modification:

Implementation Method 2

the plurality of surface features are configured to promote the removal of the molten materials along the outer surface

Methodology Applied

Scientific EffectSurface tension and capillary action: Capillary Action

Data Source

PatentUS12404218B2Article with surface structures for CMAS resistance

Publication Date: 2025.09.02 ROLLS ROYCE CORP

AI summary

In some examples, article used as a component for a turbine engine that operates in a high temperature environment. The article may include: a ceramic or ceramic matrix composite (CMC) substrate; and a coating on the ceramic or the CMC substrate, wherein the coating defines an outer surface of the article. The coating includes a plurality of surface features defining channels on the outer surface of the article. The channels are configured to modify a flow of molten Calcia-Magnesia-Alumina Silicate (CMAS) over the outer surface of the coating in a gas flow over the outer surface of the article to reduce accumulation of the molten CMAS on the outer surface of the article.