Channelled Seal Plates for Uniform CVI/CVD Densification

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Solution Overview

Problem

Conventional chemical vapor infiltration and deposition (CVI/CVD) processes for making carbon/carbon brake disks face issues with non-uniform densification across the thickness of porous structures, improper microstructure formation, and prolonged processing times.

Innovation Solution

A seal plate with a plurality of channels extending through it, featuring concentrically disposed inner and outer perimeters and varying channel widths, is used to facilitate uniform gas distribution and densification by maintaining a pressure gradient within a chemical vapor infiltration and deposition chamber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional CVI/CVD processes are used without specialized seal plates, then the processing setup is simpler, but the densification is non-uniform across the thickness of porous structures

Engineering Contradiction:

Improveuniformity of densificationVSAvoidseal plate structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The seal plate is segmented into multiple functional zones with different channel configurations. First channels extend from the inner perimeter toward the outer perimeter with varying widths, while second channels are positioned at different radial locations. This segmentation allows different regions of the porous structure to receive optimized gas flow, achieving uniform densification across the entire thickness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different channels are designed with locally optimized properties: first channels have progressively increasing widths from inner to outer perimeter to match the pressure gradient, while second channels are positioned to address specific regional needs. This local quality optimization ensures that each region of the porous structure receives appropriate gas flow for uniform densification.

Inventive Principle:

Principle #3Local quality

2Productivity

If conventional seal plates are used, then the device structure is simpler, but the processing time is prolonged

Engineering Contradiction:

Improveprocessing speedVSAvoidseal plate structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The seal plate divides the gas flow path into multiple segmented channels (first channels and second channels) that simultaneously deliver reactant gas to different regions of the porous structure. This parallel gas distribution through segmented channels significantly reduces the time required for uniform densification compared to conventional single-path gas flow.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The seal plate structure is designed to pre-establish optimal pressure gradients and gas flow paths before the CVI/CVD process begins. The channels are configured to automatically distribute gas uniformly across all regions as the process starts, eliminating the need for prolonged processing to achieve uniform densification.

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If channels with uniform width are used in seal plates, then the manufacturing is simpler, but the gas distribution is non-uniform

Engineering Contradiction:

Improvegas flow uniformityVSAvoidchannel fabrication

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The channels are designed with non-uniform widths optimized for local requirements. First channels progressively increase in width from the inner perimeter to the outer perimeter to compensate for pressure gradients, ensuring uniform gas distribution. Second channels are positioned and sized to address specific regional needs. This local quality optimization achieves superior gas flow uniformity despite increased manufacturing complexity.

Inventive Principle:

Principle #3Local quality

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 seal plate enhances uniform densification of porous structures by ensuring consistent gas flow and pressure distribution, thereby improving processing efficiency and reducing processing times.

Implementation Method 1

maintaining a pressure gradient within a chemical vapor infiltration and deposition chamber

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

chemical vapor infiltration and deposition (CVI/CVD) is a known process for making composite structures

Methodology Applied

Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Data Source

PatentUS12421597B2Seal plates for chemical vapor infiltration and deposition chambers

Publication Date: 2025.09.23 GOODRICH CORP

AI summary

A seal plate disposable between a pair of preforms for chemical vapor infiltration is disclosed. The seal plate may include a plurality of first channels that extend completely through the seal plate and that are located between an inner annulus and outer annulus of the seal plate. The seal plate may further include a plurality of second channels that also extend completely through the seal plate and that are located also between an inner annulus and outer annulus. The first channels may differ from the second channels in at least one respect (e.g., the first channels may be of a different width than the second channels). The first channels may provide an inlet for the chemical vapor infiltration of the preform, while the second channels may provide an outlet for the chemical vapor infiltration of the preform.