Adaptive CMC Surface Texturing with WJGL for EBC Adhesion

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Solution Overview

Problem

The formation process of ceramic matrix composites (CMCs) for gas turbine engine components results in surfaces that are difficult to coat effectively for high-temperature and high-pressure environments, leading to poor EBC adhesion and potential failure, necessitating messy and sub-optimal manual machining methods.

Innovation Solution

An adaptive surface texturing method using a waterjet-guided laser (WJGL) machining system integrates model-based texture design and inline optical measurement to create controlled groove patterns in the initial coating of CMC surfaces, enhancing EBC bond strength by improving wettability and avoiding material weakness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual machining methods are used to prepare CMC surfaces for coating, then surface preparation can be performed, but the process becomes messy and results in sub-optimal coating adhesion

Engineering Contradiction:

Improvecoating adhesionVSAvoidmanufacturing process cleanliness

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces manual mechanical machining with a sprayable slurry composition that chemically bonds to the CMC surface. This substitution eliminates the messiness of manual machining while creating a controlled, uniform surface preparation layer that improves coating adhesion through chemical rather than mechanical means.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the surface preparation approach from mechanical removal of material to chemical deposition of a slurry layer. By controlling the slurry composition, particle size distribution, and application parameters, the process achieves optimal surface morphology for coating adhesion without the drawbacks of manual machining.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If CMC surfaces are used directly without surface texturing, then the manufacturing process is simpler, but EBC coating adhesion is poor and air pockets form

Engineering Contradiction:

ImproveEBC coating adhesionVSAvoidsurface preparation complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies surface texturing only where needed - in the initial coating layer applied to the CMC surface. This localized texturing creates anchor points and increases surface area for EBC adhesion without requiring complex preparation of the entire CMC component. The slurry composition and application parameters are specifically tailored to create this localized surface morphology improvement.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The surface texturing is performed as a preliminary step before applying the EBC coating. By pre-treating the CMC surface with the slurry composition to create an optimized surface morphology, the subsequent EBC coating application achieves better adhesion and fewer air pockets without requiring complex in-situ processing during coating application.

Inventive Principle:

Principle #10Preliminary action

3Area of stationary object

If the initial coating layer is made thicker to improve coverage, then surface coverage is better, but the surface undulation and coating uniformity worsen

Engineering Contradiction:

Improvesurface coverageVSAvoidsurface uniformity

Core Design Contradiction:

Area of stationary objectVSManufacturing precision

Solution Approach 1:

The patent optimizes the slurry composition parameters including particle size distribution, binder content, and solvent selection to achieve complete surface coverage while maintaining uniform thickness. By carefully controlling these parameters, the slurry fills surface voids and creates a uniform initial coating layer that provides both adequate coverage and smooth surface morphology for subsequent EBC application.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The initial coating layer is formulated as a composite slurry material containing ceramic particles, binders, and solvents in specific ratios. This composite structure allows the coating to flow into and cover surface irregularities while the binder system ensures uniform distribution and adhesion, achieving both complete coverage and surface uniformity simultaneously.

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 method improves EBC adhesion and durability on CMC surfaces, reducing the risk of failure and extending part life by creating controlled surface patterns that enhance bonding and prevent air pocket formation.

Implementation Method 1

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentUS12371389B2Adaptive surface texturing for ceramic matrix composites

Publication Date: 2025.07.29 RTX CORP

AI summary

An adaptive surface texturing method is provided for use with a part formed of ceramic matrix composites (CMCs) to be coated with an environmental barrier coating (EBC). The method includes coating a CMC surface of the part with an initial coating, determining a contour and an undulation pattern of the CMC surface and designing a texturing pattern to follow the contour and the undulation pattern and to be formed in the initial coating based on a thickness of the initial coating and an average particle size of a slurry of the EBC.