CMC Component with Porous Core for Uniform CVI Infiltration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing chemical vapor infiltration (CVI) process for fabricating ceramic matrix composite (CMC) components is hindered by surface pores filling before the interior, leading to non-uniform density and infiltration issues.

Innovation Solution

A ceramic matrix component with a fibrous core having greater porosity than the surrounding preform, optionally featuring ceramic foam, sacrificial fibers, and cooling passages, is fabricated using CVI, allowing improved access and uniform infiltration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If CVI process is used to deposit matrix around preform fibers, then ceramic matrix composite component is formed, but surface pores become filled with matrix before the interior causing non-uniform density

Engineering Contradiction:

Improvedensity uniformityVSAvoidinfiltration process

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

A ceramic foam core with high porosity (75-90%) is introduced as the fibrous core. This porous structure allows the CVI process to penetrate deep into the interior of the preform, enabling uniform matrix distribution throughout the component while maintaining manufacturing feasibility

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The ceramic foam core acts as an intermediary structure that facilitates the CVI process. It provides a porous pathway that allows matrix precursor to reach the interior of the preform, mediating between the surface deposition and interior infiltration to achieve uniform density distribution

Inventive Principle:

Principle #24Intermediary (Mediator)

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 approach enhances infiltration, reduces stress, and results in CMC components with more uniform density and improved structural integrity, addressing the challenges of surface pore filling and non-uniform density.

Implementation Method 1

forming a ceramic matrix on the fibrous preform using chemical vapor infiltration

Methodology Applied

Scientific EffectChemical vapor infiltration: Chemical Vapour Deposition

Data Source

PatentEP3868556B1Ceramic matrix composite component having low density core and method of making the CMC component

Publication Date: 2025.03.26 RTX CORP

Figure 1
Figure 2~3

AI summary

Disclosed is a ceramic matrix component having a fibrous core and a ceramic matrix composite shell surrounding at least a portion of the fibrous core. The ceramic matrix composite shell comprises a fibrous preform. The fibrous core has a greater porosity than the fibrous preform. A method of making the ceramic matrix component is also disclosed. The method includes forming a ceramic matrix on the fibrous preform using chemical vapor infiltration.