Integral CMC Fastener for Gas Turbine Leakage

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Solution Overview

Problem

Ceramic matrix composite (CMC) components in aerospace and industrial gas turbine engines face challenges with low through-thickness and interlaminar properties, leakage, and tolerance issues in attachment methods, particularly with traditional fasteners.

Innovation Solution

A single-piece ceramic matrix composite gas turbine engine component is formed with an integrally formed fastener, using a rigidized preform structure made from polymer-based material, which is infiltrated with a matrix material to create a monolithic structure, eliminating gaps and improving interlaminar properties and tolerance control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate CMC fastener is used to connect CMC component to metal support structure, then attachment capability is achieved, but leakage occurs around the fastener head and manufacturing complexity increases

Engineering Contradiction:

Improveattachment capabilityVSAvoidgas leakage

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The fastener is merged with the CMC component body to form a single integral structure. The fastener is formed as part of the component during the same manufacturing process, eliminating the separate fastener assembly step and removing the source of leakage around fastener heads.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The fastener is formed preliminarily as part of the component body during the initial CMC manufacturing process. This preliminary integration ensures that the fastener and component are manufactured as one piece, eliminating subsequent assembly issues and leakage problems.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If a flat panel fastener is used, then attachment is achieved, but processing expenses increase and tolerance control becomes difficult

Engineering Contradiction:

Improveattachment capabilityVSAvoidprocessing expenses

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The fastener is combined with the CMC component body into a single integral structure. This merging eliminates the need for separate fastener manufacturing, machining, and assembly operations, significantly reducing processing expenses and simplifying tolerance control.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The CMC component body serves multiple functions: it provides the structural component function and simultaneously provides the fastener function. This multi-functionality eliminates the need for separate fasteners and reduces overall manufacturing complexity and cost.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If traditional attachment methods are used, then CMC component can be attached to metal support structure, but through-thickness and interlaminar properties remain low

Engineering Contradiction:

Improveattachment capabilityVSAvoidthrough-thickness and interlaminar properties

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The fastener is made from the same ceramic matrix composite material as the component body, creating a composite-to-composite attachment. This eliminates the weak interface between CMC and metal support structures, improving through-thickness and interlaminar strength by matching material properties.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

By merging the fastener with the component body as a single integral CMC structure, the attachment interface is eliminated. The fastener and component are made from the same material with matched properties, maximizing the strength and reliability of the attachment to the metal support structure.

Inventive Principle:

Principle #5Merging (Combining)

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

This approach enhances the interlaminar properties of CMC components, prevents gas leakage, reduces fabrication expenses, and simplifies tolerance control, resulting in a robust and cost-effective attachment method for CMC components in gas turbine engines.

Implementation Method 1

the rigid perform structure is oxidized to remove the polymer based material prior to being infiltrated with the matrix material

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 2

the matrix material is infiltrated into the fibers of the rigidized preform structure and the weave of the fiber fastener to form the ceramic matrix composite component with the fastener as a monolithic structure

Methodology Applied

Scientific EffectInfiltration: Permeation

Data Source

PatentUS12024474B2Integral ceramic matrix composite fastener with polymer rigidization

Publication Date: 2024.07.02 RTX CORP

AI summary

A gas turbine engine component includes a gas turbine engine component body formed of a ceramic matrix composite material having at least one fastener integrally formed with the gas turbine engine component body as a single-piece structure. The gas turbine engine component body initially comprises a rigidized preform structure formed from a polymer based material. The at least one fastener connects the gas turbine engine component body to an engine support structure.