CMC Turbine Component Surface Roughness Tuning for Coating

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Solution Overview

Problem

The formation process of ceramic matrix composite (CMC) components for gas turbine engines is difficult and results in surfaces that are either too smooth or too rough for effective coating, leading to sub-optimal results and messy manual machining.

Innovation Solution

A method involving autonomous adaptive machining to identify and adjust the surface roughness of CMC components to specific levels, using robotic tools to increase or decrease roughness as needed, ensuring compatibility with high-temperature and high-pressure coatings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If CMCs are used as materials for gas turbine engine components, then improved strength and heat resistance are achieved, but the formation process becomes difficult and surface quality is poor

Engineering Contradiction:
ImprovestrengthVSAvoidformation process difficulty
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by performing surface machining operations after component formation but before coating application. The system identifies surface roughness deficiencies in advance and corrects them through automated machining, ensuring surfaces are properly prepared for coating before the coating process begins. This prevents coating failures and eliminates the need for messy manual cleanup operations.

Inventive Principle:
Principle #10Preliminary action

2Temperature

If CMCs are used as materials for gas turbine engine components, then improved heat resistance is achieved, but the formation process becomes difficult and surface quality is poor

Engineering Contradiction:
Improveheat resistanceVSAvoidformation process difficulty
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent applies self-service by implementing an automated feedback control system where sensors continuously monitor surface roughness during machining, and the system automatically adjusts machining parameters and tool positions without human intervention. The robotic system services itself by identifying and correcting its own surface preparation deficiencies, eliminating the need for manual inspection and cleanup operations.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If manual machining is used to prepare surfaces, then surface roughness can be adjusted, but the process is messy and requires significant cleanup

Engineering Contradiction:
Improvesurface roughness controlVSAvoidmess and cleanup requirements
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent replaces manual mechanical machining with an automated robotic machining system. The robotic system uses programmable motion control and automated tool changing to perform precise surface machining operations. This substitution eliminates the mess associated with manual machining tools while maintaining or improving surface roughness control through consistent, repeatable automated processes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If surfaces are too smooth or too rough, then coating application is compromised, but manual machining to correct this is messy and inefficient

Engineering Contradiction:
Improvecoating qualityVSAvoidcoating preparation efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies feedback by implementing a closed-loop control system where sensors continuously measure surface roughness during the machining process. The measured surface roughness data is fed back to the control system, which automatically adjusts machining parameters such as tool speed, feed rate, and tool position to maintain the target surface roughness range. This ensures optimal coating preparation while eliminating messy manual operations.

Inventive Principle:
Principle #23Feedback

5Manufacturing precision

If autonomous adaptive machining is implemented, then surface roughness is precisely controlled for optimal coating, but device complexity increases

Engineering Contradiction:
Improvesurface roughness controlVSAvoidmachining system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by systematically varying machining parameters such as tool speed, feed rate, depth of cut, and tool position based on real-time surface roughness measurements. The control system maintains a library of optimized parameter combinations and automatically selects and adjusts parameters to achieve the target surface roughness range. This approach achieves precise surface control while managing system complexity through programmable parameter management.

Inventive Principle:
Principle #35Parameter changes

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 the surface preparation of CMC components, enabling optimal coating and reducing waste and manual cleanup, while enhancing the performance and reliability of gas turbine engine components.

Implementation Method 1

machining the first sectors to increase the surface roughness to greater than the first roughness level and machining the second sectors to decrease the surface roughness to less than the second roughness level

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP4190765A1Method of forming a component for use in a gas turbine engine
Publication Date: 2023.06.07 RTX CORP
  • EP4190765A1 patent drawingFigure 1
  • EP4190765A1 patent drawingFigure 2~3
  • EP4190765A1 patent drawingFigure 4

AI summary

A method of forming an aerodynamic component for use in a gas turbine engine using ceramic matrix composites (CMCs) is provided. The method includes executing a full densification of the CMCs once a final shape of the aerodynamic component is achieved, identifying first sectors (310) of an exterior surface (301) of the aerodynamic component which have a surface roughness of less than a first roughness level and identifying second sectors (320) of the exterior surface (301) of the component which have a surface roughness of greater than a second roughness level, machining the first sectors (310) to increase the surface roughness to greater than the first roughness level and machining the second sectors (320) to decrease the surface roughness to less than the second roughness level.