3D Woven Composite Preform Fabrication via CVI
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Solution Overview
Problem
The fabrication of complex-shaped parts from composite materials is challenging due to difficulties in creating fiber preforms through three-dimensional weaving, which often results in weak connections between assembled portions and increased complexity and cost.
Innovation Solution
A method involving three-dimensional weaving of continuous fiber strips, cutting individual blanks, shaping them to the desired form, and densifying with a matrix using chemical vapor infiltration, with optional surface treatments and interphase layers to enhance strength and deformation capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If fiber preforms are made by three-dimensional weaving for complex-shaped parts, then the mechanical properties and strength of the composite material part are improved, but it becomes difficult or impossible to make the preform directly and requires assembly of separate parts which creates weak connection points
Solution Approach 1:
The method segments the complex-shaped part into multiple fiber blanks that are woven separately into a continuous strip, then assembled together to form the complete preform. This allows each blank to be optimized for 3D weaving while the final assembly creates the complex shape, resolving the contradiction between maintaining mechanical strength through 3D weaving and achieving complex geometries.
Solution Approach 2:
The invention merges multiple individually woven fiber blanks into a continuous strip through a weaving process that creates interlacing connections. This combining approach maintains the mechanical benefits of 3D weaving in each blank while achieving the complex overall shape through assembly, eliminating the weak connection points associated with traditional separate-part assembly.
2Shape
If multiple separate parts are assembled to form complex-shaped preforms, then the complex shape is achieved, but the connections between portions become points of weakness
Solution Approach 1:
Multiple fiber blanks are merged into a continuous woven strip where the weaving process creates interlacing connections that are structurally integrated rather than merely assembled. This merging maintains reliability by creating continuous fiber paths and interlocked connections throughout the complex-shaped preform, eliminating weak assembly points.
Solution Approach 2:
The invention uses composite construction where fiber blanks of different orientations and properties are combined in a woven strip. This composite approach allows each blank to contribute its optimized mechanical properties while the weaving creates a integrated structure where the connections between blanks are as strong as the blanks themselves, resolving the reliability issue.
3Manufacturing precision
If traditional methods are used to make fiber preforms for complex parts, then the process requires great deal of manipulation including surface treatment, interphase formation, and consolidation, but this increases the complexity and cost of fabrication
Solution Approach 1:
Surface treatments and interphase formation are performed on the fiber blanks before they are woven into the continuous strip. This preliminary action allows these critical quality-enhancing steps to be applied to individual blanks where they are more easily controlled, reducing the overall process complexity while maintaining manufacturing precision in the final preform.
Solution Approach 2:
The fabrication process is segmented into distinct stages: surface treatment of individual blanks, weaving into continuous strip, and final consolidation. This segmentation allows each operation to be optimized independently, reducing overall process complexity while maintaining high manufacturing precision through specialized processing at each stage.
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 simplifies the production of complex composite parts by allowing simultaneous treatment of multiple blanks, reducing weaknesses in connections, and improving mechanical properties, making it suitable for applications like turbomachine blades.
Implementation Method 1
Gas consolidation comprises partially densifying the preform by depositing a material on the fibers by chemical vapor infiltration (CVI)
Implementation Method 2
Liquid consolidation comprises impregnating the preform with a consolidation composition containing a resin and applying heat treatment to cure and pyrolyze the resin
Data Source
AI summary
A method of fabricating a complex part out of composite material including three-dimensional woven fiber reinforcement densified by a matrix, the method including three-dimensionally weaving a continuous fiber strip including a succession of fiber blanks for preforms of a plurality of parts that are to be fabricated; subsequently cutting individual fiber blanks out from the strip, each blank being a one-piece blank; shaping a cut-out blank to obtain a one-piece fiber preform having a shape that is close to the shape of a part that is to be fabricated; consolidating the preform in the desired shape; and densifying the consolidated preform by forming a matrix by chemical vapor infiltration.