Commingled Fiber Preform Architecture for Uniform Composite Densification
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Solution Overview
Problem
Existing methods for manufacturing composite preforms face challenges in achieving uniform gas infiltration during densification due to inadequate pathways, leading to components with less than 10% open porosity.
Innovation Solution
A commingled fiber preform architecture is developed, utilizing layers of commingled fibers with varying percentages of carbon, fusible, and fugitive fibers, which are pyrolyzed to create pathways for fluid infiltration, and reinforced through thickness reinforcement (TTR) to ensure uniform densification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If dry fabric preform is used for carbon-carbon manufacturing, then in-plane strength is maintained, but uniform densification is hindered due to inadequate gas infiltration pathways
Solution Approach 1:
The patent applies local quality by creating fabric layers with spatially varying fiber compositions. Different regions of the preform contain different percentages of fugitive, fusible, and carbon fibers tailored to local densification needs. This enables uniform gas infiltration throughout the preform while maintaining in-plane strength in load-bearing regions.
Solution Approach 2:
The patent incorporates fugitive fibers that are pyrolyzed to create porous pathways within the preform structure. These porous channels enable gas to infiltrate uniformly into the center of the preform during densification, solving the inadequate gas flow path problem while the remaining carbon fiber structure maintains mechanical strength.
2Strength
If fiber volume is increased to maintain structural integrity, then strength is improved, but gas infiltration pathways become inadequate
Solution Approach 1:
The patent uses composite fabric layers combining three types of fibers (fugitive, fusible, and carbon) in specific ratios. This composite structure allows the preform to simultaneously achieve structural integrity from carbon fibers and adequate gas infiltration pathways from the pyrolyzed fugitive fiber network, resolving the contradiction between strength and infiltration capability.
Solution Approach 2:
The patent introduces fusible fibers as an intermediary material that facilitates gas infiltration during processing. These fibers create temporary pathways that enable uniform densification, and are subsequently converted into part of the final carbon matrix structure, thus mediating between the need for structural integrity and infiltration capability.
3Ease of manufacture
If traditional densification methods are used, then manufacturing process is simple, but open porosity remains less than 10%
Solution Approach 1:
The patent applies preliminary action by pre-configuring the fabric layers with specific fiber compositions and arrangements before densification. The fugitive and fusible fibers are strategically placed to create optimal infiltration pathways in advance, enabling uniform gas penetration and achieving greater than 10% open porosity without complicating the manufacturing process.
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 solution provides numerous pathways for uniform gas infiltration, enhancing densification and maintaining high in-plane strengths, resulting in improved composite components.
Implementation Method 1
The first fugitive fibers and the third fugitive fibers are pyrolyzed from the first fabric layers and the second fabric layer to create a path through a thickness of the first fabric layers and the second fabric layer for infiltration of fluids
Implementation Method 2
fusible fibers are converted into a carbon matrix
Data Source
AI summary
A preform is provided. The preform includes first fabric layers that include a first set of commingled fibers and a second set of commingled fibers. The preform includes a second fabric layer positioned between the first fabric layers. The second fabric layer includes a third set of commingled fibers and a fourth set of commingled fibers. The first set of commingled fibers includes a lower percentage of the at least one of first carbon fibers or first fusible fibers than the third set of commingled fibers, The first set of commingled fibers include a higher percentage of first fugitive fibers than the third set of commingled fibers. The first fugitive fibers and the third fugitive fibers are pyrolyzed from the first fabric layers and the second fabric layer.