Ceramic Matrix Composite Preform Channels for Uniform Vapor Infiltration
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Solution Overview
Problem
Current methods for forming ceramic matrix composites result in non-uniform microstructures due to uneven infiltration of chemical vapor, leading to less desirable physical properties.
Innovation Solution
Employing a preform with direct channels extending from the exterior to the interior, free of char, and maintaining consistent directionality and diameter, facilitates uniform chemical vapor infiltration, resulting in a more uniform and dense microstructure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods are used to form ceramic matrix composites, then the manufacturing process is simpler, but the microstructure is non-uniform leading to less desirable physical properties
Solution Approach 1:
The preform is segmented into multiple layers with through-thickness channels created by removing specific tows. This segmentation allows chemical vapor to access the interior from multiple directions, ensuring uniform infiltration throughout the entire preform volume and eliminating non-uniform microstructures.
Solution Approach 2:
The invention introduces through-thickness channels that extend in the vertical dimension (through the thickness of the preform). This adds a third dimension to the infiltration pathway, allowing chemical vapor to penetrate from exterior surfaces through to the interior space, achieving uniform infiltration that cannot be accomplished with conventional planar approaches.
2Productivity
If direct channels are introduced to improve infiltration uniformity, then the infiltration process becomes faster and more uniform, but the preform manufacturing process becomes more complex
Solution Approach 1:
The direct channels are formed during the preform manufacturing process itself by removing specific tows before infiltration. This preliminary action creates the infiltration pathways in advance, eliminating the need for post-manufacturing modifications and simplifying the overall manufacturing process despite the added step of tow removal.
Solution Approach 2:
The channels are strategically positioned at specific locations within the preform where tow removal is required. By applying local quality changes (removing tows only where needed to create channels), the manufacturing complexity is minimized while achieving the desired uniform infiltration throughout the preform.
3Manufacturing precision
If channels are made to extend from exterior to interior, then infiltration uniformity improves, but the channel formation process becomes more difficult
Solution Approach 1:
The channel formation process is segmented into discrete tow removal steps for each layer. By segmenting the preform into layers and removing tows systematically in each layer, the complex task of creating through-thickness channels is broken down into manageable steps that maintain precise directional control.
Solution Approach 2:
The channel directions are predetermined during preform construction by selecting which tows to remove in each layer. This preliminary planning ensures that channels will extend in the desired directions (including perpendicular orientations) from exterior to interior, eliminating the need for complex real-time adjustments during infiltration.
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 direct channels allow for quicker and more uniform infiltration, producing a ceramic matrix composite with enhanced physical properties.
Implementation Method 1
The composites are an attractive material for various applications in which high temperature durability and light weight are desired. Ceramic matrix composites can be formed by infiltrating a preform with a vapor (chemical vapor infiltration) to form the matrix.
Data Source
Figure 1
Figure 2~3
AI summary
Disclosed is a preform for a ceramic matrix composite including direct channels extending from an exterior surface of the preform to an interior space of the preform wherein the direct channels are free of char.