Graphite-Resin Brake Preform for Low-Waste C/C Fabrication
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Solution Overview
Problem
The high cost and material wastage associated with traditional methods of fabricating carbon fiber carbon matrix composite (C/C) components for aircraft brake systems, where 50% or more of the material is cut away and 50% of the preform weight is lost during carbonization and densification, resulting in a final product that is only 15-25% of the original mass.
Innovation Solution
A method involving the formation of fibrous preforms by layering carbonized open-braid fabric, open-weave fabric, and/or stretch-broken fabric with a graphite powder and phenolic resin compound mixture, followed by densification using chemical vapor deposition (CVD), which reduces material loss and time, and includes varying graphite particle sizes to control fiber volume and densification efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If traditional preform fabrication methods are used (stacking and needling oxidized polyacrylonitrile fiber fabric), then the preform can be formed, but 50% or more of the material is cut away and wasted
Solution Approach 1:
Instead of starting with fabric and cutting away material, the invention inverts the approach by building the preform through layering graphite powder and phenolic resin compound mixtures between textile layers, then carbonizing the entire structure. This eliminates the need to cut away 50% or more of the material, as the preform is constructed in its final shape from the beginning.
Solution Approach 2:
The invention changes the material parameters by using graphite powder and phenolic resin compound mixtures instead of traditional oxidized polyacrylonitrile fiber fabric. This parameter change allows the preform to be built up layer by layer without subsequent cutting, dramatically reducing material wastage while maintaining manufacturability.
2Loss of substance
If traditional carbonization and densification processes are used, then the preform is converted to C/C composite, but 50% of the preform weight is lost during carbonization and additional material is removed during CVD densification
Solution Approach 1:
The invention incorporates graphite powder and phenolic resin compound mixtures as preliminary carbon sources within the preform structure before carbonization. During the carbonization process, these pre-positioned carbon sources convert to graphite, providing in-situ carbon reinforcement that compensates for the weight loss from fiber decomposition, thereby maintaining composite performance while reducing overall weight loss.
Solution Approach 2:
The phenolic resin compound acts as an intermediary material that facilitates the carbonization process. It decomposes to form carbon structures that fill voids and reinforce the composite, mediating between the original fiber structure and the final C/C composite, thus reducing weight loss while ensuring structural integrity.
3Productivity
If traditional preform fabrication is used, then the preform can be manufactured, but the process is time-consuming and expensive
Solution Approach 1:
The invention segments the preform fabrication into discrete layering steps where graphite powder and phenolic resin compound mixtures are applied between textile layers. This segmentation allows for systematic, repeatable manufacturing that reduces overall process time and cost, as each layer can be prepared and applied independently without complex cutting and assembly operations.
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 method significantly reduces material wastage and production time, achieving a densified composite component with improved frictional and wear performance while maintaining a substantial portion of the original material's mass, thus lowering production costs and enhancing the efficiency of brake system components.
Implementation Method 1
the phenolic resin in the first graphite powder and phenolic resin compound mixture layer and the second graphite powder and phenolic resin compound mixture layer is carbonized during the densification
Implementation Method 2
densifying the fibrous preform
Data Source
AI summary
A method of fabricating a composite component is provided. The method includes forming a fibrous preform by: forming a first graphite powder and phenolic resin compound mixture layer over a first textile layer, the first graphite powder and phenolic resin compound mixture layer having a first group of graphite particles; disposing a second textile layer over the first graphite powder and phenolic resin compound mixture layer; forming a second graphite powder and phenolic resin compound mixture layer over the second textile layer, the second graphite powder and phenolic resin compound mixture layer having a second group of graphite particles; and disposing a third textile layer over the second graphite powder and phenolic resin compound mixture layer; and densifying the fibrous preform.