Internal Cooling Circuits for Ceramic Matrix Composite Components

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Solution Overview

Problem

Conventional methods for incorporating complex cooling channels into ceramic matrix composite (CMC) components, crucial for maintaining high-temperature performance and durability in gas turbine engines, are inadequate as they do not effectively allow for integral cooling circuits within these materials.

Innovation Solution

A method involving partial densification of fiber preforms, machining channels for cooling, covering these channels with a fibrous member to form a near net shape preform, and subsequent full densification to maintain internal cooling passages, enabling the creation of CMC components with integrated cooling features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional methods are used to create cooling channels in CMC components, then manufacturing simplicity is maintained, but the ability to form integral complex cooling circuits is lost

Engineering Contradiction:

Improveability to form integral complex cooling circuitsVSAvoidmanufacturing process complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The method performs preliminary actions by partially densifying the fiber preform before machining the cooling channels. This preliminary densification provides a stable substrate for machining while allowing subsequent steps (covering channels with fibrous member, final densification) to complete the integral cooling circuit formation. The preliminary action enables complex internal passages to be created that would not be possible with fully densified material.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The manufacturing process is segmented into distinct stages: partial densification, channel machining, channel covering with fibrous member, and final densification. This segmentation allows each step to be optimized independently - machining is performed on partially densified material which is easier to work with, while final densification occurs after channels are sealed, ensuring structural integrity.

Inventive Principle:

Principle #1Segmentation

2Strength

If fiber preform is fully densified before machining channels, then structural integrity is maximized, but channel formation becomes difficult

Engineering Contradiction:

Improvestructural integrityVSAvoidchannel formation ease

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The method applies partial densification rather than full densification at the machining stage. This partial action provides sufficient structural integrity to handle the preform during machining operations while maintaining the porosity and softness needed for easy channel formation. The remaining densification is completed after channel formation, ensuring both ease of manufacture and final structural integrity.

Inventive Principle:

Principle #16Partial or excessive action

3Strength

If cooling channels are machined into fully densified CMC, then material strength is maintained, but complex internal passages cannot be formed

Engineering Contradiction:

Improvematerial strengthVSAvoidcomplex internal passages formation

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The method performs preliminary channel formation in partially densified material where complex geometries can be easily machined. The preliminary action of creating channels in the softer, partially densified state enables complex internal passages that would be impossible to machine in fully densified material. Final densification then strengthens the material while preserving the complex channel geometry.

Inventive Principle:

Principle #10Preliminary action

4Ease of manufacture

If partial densification is performed before channel machining, then channel formation becomes easier, but final densification must maintain internal passages

Engineering Contradiction:

Improvechannel machining easeVSAvoidinternal passage maintenance

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The fibrous member acts as an intermediary that is placed over the machined channels before final densification. This intermediary element seals the channels and prevents them from collapsing or filling during the final densification process. The fibrous member mediates between the easy-to-machine partially densified state and the high-strength final densified state, ensuring internal passages are maintained throughout the process.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11643948B2Internal cooling circuits for CMC and method of manufacture

Publication Date: 2023.05.09 RTX CORP

AI summary

A method for forming a ceramic matrix composite (CMC) component with an internal cooling channel includes partially densifying a first fiber preform to form a portion of a final ceramic matrix volume, machining a first channel into a surface of the partially densified first fiber preform, covering the first channel with a fibrous member to form a near net shape fiber preform with an internal passage formed by the first channel and the fibrous member, and densifying the near net shape fiber preform.