3D Woven Composite Fiber Texture for Uniform CVI Densification

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for producing thermostructural composite material parts with smooth surfaces and uniform densification during chemical vapor infiltration (CVI) face challenges such as steep densification gradients and surface irregularities, requiring additional operations like surface trimming and adding 2D plies.

Innovation Solution

A fiber texture is woven with a core made by three-dimensional interlock weaving using discontinuous fibers and a skin made by plain, satin, or twill type weaving using continuous filaments, allowing for uniform CVI densification and maintaining a smooth surface without significant irregularities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If three-dimensional weaving with discontinuous fibers and covering yarn is used to enhance gas access and subdivision of pores, then densification uniformity is improved, but surface irregularities occur requiring additional trimming operations

Engineering Contradiction:

Improvedensification uniformityVSAvoidsurface smoothness

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The fiber texture is divided into two distinct portions: a core made by three-dimensional weaving with discontinuous fibers for enhanced gas access and pore subdivision, and a skin made by weaving with continuous filaments for surface smoothness. This segmentation allows each portion to fulfill its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the fiber texture are assigned different qualities: the core uses discontinuous fibers with bulking characteristics to promote uniform densification, while the skin uses continuous filaments to maintain surface smoothness. This local differentiation resolves the contradiction between densification uniformity and surface quality.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If covering yarn is eliminated after weaving to allow discontinuous filaments to bulk up, then pore subdivision is enhanced, but surface irregularities are created requiring additional processing

Engineering Contradiction:

Improvepore subdivisionVSAvoidadditional processing time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The covering yarn is extracted or eliminated after the weaving process to allow the discontinuous filaments in the core to bulk up and create subdivided pores. This extraction is necessary to achieve the desired pore structure while the skin portion maintains surface integrity.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The covering yarn is removed in a preliminary step before densification to enable the discontinuous filaments to bulk up and create the desired pore subdivision. This preliminary action prepares the core structure for uniform densification without requiring subsequent surface trimming.

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If surface trimming and adding 2D plies are performed to achieve smooth surface state, then surface quality is improved, but manufacturing complexity and processing steps increase

Engineering Contradiction:

Improvesurface qualityVSAvoidprocessing steps

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The functions of surface smoothness and structural reinforcement are merged into a single skin portion made by weaving with continuous filaments. This eliminates the need for separate surface trimming operations and additional 2D plies, reducing overall processing complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The skin portion serves multiple functions simultaneously: it provides surface smoothness, maintains structural integrity, and facilitates gas access to the core. This multi-functionality eliminates the need for separate processing steps for surface finishing and structural reinforcement.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 ensures uniform densification throughout the part, reduces the need for additional processing steps, and enhances the mechanical properties of the composite material while maintaining a smooth surface finish.

Implementation Method 1

it can be useful to provide easy access for the gas to the core of the fiber texture or to ensure that the fiber texture presents porosity that is relatively uniform in order to achieve densification that departs as little as possible from being uniform

Methodology Applied

Scientific EffectChemical vapor infiltration: Chemical Vapour Deposition

Data Source

PatentUS8426326B2Fiber reinforcing texture for making a composite material part

Publication Date: 2013.04.23 SAFRAN CERAMICS SA

AI summary

A fiber reinforcing texture woven as a single part for fabricating a composite material part having an inner portion, or core, made by three-dimensional weaving with yarns made up from discontinuous fibers, and a portion adjacent to an outside surface, or skin, made by weaving with yarns made up from continuous filaments.