Stacking Tool Fixture Tower With Forced Flow for CVI
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional chemical vapor infiltration (CVI) processes are inefficient and time-consuming, leading to increased production costs due to the slow infiltration of porous preforms, which results in prolonged hours-on-gas time before appreciable rigidization/infiltration is achieved.
Innovation Solution
A tooling assembly comprising a tower of tooling fixtures with a central channel and perforated walls, allowing forced flow of vaporous precursors through the fixtures to enhance infiltration efficiency, utilizing interlocking features for stability and a weighted lid to manage pressure differentials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional CVI process is used, then composite quality is maintained, but infiltration time is excessively long
Solution Approach 1:
The preform is divided into multiple segments or zones, with tooling fixtures arranged in a tower configuration with a central channel. This segmentation allows forced flow of vaporous precursors through specific pathways, targeting different regions of the preform simultaneously and reducing overall infiltration time while maintaining composite quality.
Solution Approach 2:
The patent employs forced flow of vaporous precursors through the preform using pressure differentials created by the tooling assembly configuration. The central channel and surrounding fixtures direct gas flow through the preform, replacing slow diffusion with forced convection, thereby significantly reducing infiltration time while preserving matrix deposition quality.
2Productivity
If forced flow approach is used, then infiltration time is reduced, but process complexity increases
Solution Approach 1:
The tooling assembly is segmented into modular fixtures that can be arranged in different configurations. Each fixture is a standardized component with specific flow paths, allowing the system to achieve forced flow capability through modular assembly rather than a single complex device, thus managing complexity while maintaining productivity benefits.
Solution Approach 2:
The tooling fixtures are designed as universal components that can be arranged in various configurations to handle different preform sizes and geometries. The central channel design and fixture geometry serve multiple functions: directing gas flow, supporting preform segments, and creating pressure differentials, thereby reducing the need for additional specialized components.
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 forced flow approach significantly reduces infiltration time, enhancing production efficiency without compromising composite quality, allowing for faster matrix deposition in porous preforms.
Implementation Method 1
The CVI process can be used to fill in the voids of a porous preform and form the matrix to create a composite. The CVI process relies primarily on diffusion of vaporous precursors around the porous preform to deposit the matrix material.
Implementation Method 2
The CVI process relies primarily on diffusion of vaporous precursors around the porous preform to deposit the matrix material.
Data Source
AI summary
A tooling assembly suitable for use in chemical vapor infiltration (CVI) comprises a plurality of tooling fixtures arranged as a tower, with a central channel extending therethrough along a channel axis, and a lid atop the tower and covering the central channel. Each tooling fixture of the plurality of tooling fixtures comprises a plurality of walls defining an internal volume, and a plurality of holes through at least one wall of the plurality of walls, the plurality of holes placing the internal volume in flow communication with an external environment. Each tooling fixture of the plurality of tooling fixtures is in physical contact with an adjacent tooling fixture.