Additive Graphite Tooling for Conformal CMC Infiltration
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Solution Overview
Problem
Traditional tooling for ceramic matrix composite (CMC) fabrication is difficult to tailor for complex shapes and often results in non-conformal designs, leading to inefficient precursor infiltration and high costs.
Innovation Solution
The method involves generating a conformal model of the tooling fixture using additive manufacturing with carbon-containing ink, which is then extruded layer-by-layer and consolidated to create a tooling fixture that matches the geometry of the fibrous preform, optimizing porosity and strength for uniform precursor flow during chemical vapor infiltration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional machined graphite blocks with uniform thickness are used, then manufacturing simplicity is maintained, but the tooling cannot be tailored to complexly-shaped preforms
Solution Approach 1:
The patent applies parameter changes by transitioning from uniform thickness to variable thickness in the tooling design, allowing the tooling to conform to complex preform geometries. The additive manufacturing process enables continuous variation of geometric parameters to match the specific shape requirements of different preforms.
Solution Approach 2:
The invention moves from traditional 2D/3D machining to 4D additive manufacturing, where the tooling geometry can vary in all three spatial dimensions plus thickness. This enables conformal tooling that wraps around complex preform shapes, achieving adaptability that was impossible with conventional machining methods.
2Manufacturing precision
If conformal tooling is designed to match complex preform geometries, then precursor infiltration uniformity is improved, but manufacturing difficulty increases
Solution Approach 1:
The patent replaces traditional mechanical machining processes with additive manufacturing technology. Instead of using complex CNC machining operations to create conformal geometries, the invention uses digital modeling and layer-by-layer material deposition, significantly simplifying the manufacturing process while maintaining high geometric precision.
Solution Approach 2:
The invention changes the manufacturing approach from subtractive (machining) to additive (deposition), enabling complex conformal geometries to be manufactured more easily. The parameter change in manufacturing methodology allows for precise control of tooling geometry to match preform shapes without the complexity of traditional machining.
3Productivity
If uniform thickness tooling is used, then manufacturing simplicity is maintained, but infiltration hole distribution is suboptimal for complex shapes
Solution Approach 1:
The patent applies local quality by varying the thickness of the tooling in different regions to optimize precursor infiltration. Thinner regions allow for better gas flow and infiltration in areas that require it, while thicker regions provide structural support. This localized variation in thickness optimizes infiltration efficiency for complex preform geometries.
Solution Approach 2:
The invention utilizes porous tooling structures with strategically distributed infiltration holes that vary in density and size according to the local requirements of the preform geometry. The porous design allows gaseous precursors to infiltrate efficiently through regions with higher porosity, improving overall infiltration productivity.
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 allows for the creation of tooling fixtures that conform to complex preform geometries, ensuring uniform precursor infiltration, reducing fabrication costs and lead times, and enhancing the quality of CMC components.
Implementation Method 1
consolidating the extruded carbon-containing ink to form a consolidated tooling fixture
Data Source
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AI summary
A method of fabricating a tooling fixture (10, 110) suitable for use in infiltrating a fibrous preform (12, 112) includes generating a model of the tooling fixture (10, 110), the model being conformal and complementary to a geometry of the fibrous preform (12, 112), additively manufacturing the tooling fixture (10, 110) by extruding a carbon-containing ink in a layer-by-layer manner, and consolidating the extruded carbon-containing ink to form a consolidated tooling fixture (10, 110).