Perforated Tooling for Composite Preform Needling and Densification
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Solution Overview
Problem
Existing methods for manufacturing composite materials, such as carbon/carbon (C/C) composites, face challenges in efficiently generating through-thickness reinforcement and achieving uniform densification, particularly during the needling and heat treatment processes.
Innovation Solution
A preform tooling arrangement comprising a base plate with a male die surface and a stripper plate with a female die surface, both featuring perforations for textile needles, allows for through-thickness needling and subsequent chemical vapor infiltration (CVI) densification, enabling improved interlaminar strength and uniform density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional needling methods are used for through-thickness reinforcement, then interlaminar strength is improved, but manufacturing complexity and time increase due to multiple fixtures and processes
Solution Approach 1:
The patent combines the needling process and CVI densification process into a single integrated tooling system. The base plate with perforations allows textile needles to pass through for needling, while the same perforations later allow gas flow for CVI densification. This eliminates the need for separate fixtures and handling steps, reducing manufacturing complexity while maintaining interlaminar strength improvements.
Solution Approach 2:
The base plate serves multiple functions: it provides structural support during needling, allows needle passage through perforations for through-thickness reinforcement, and subsequently serves as a gas distribution manifold for CVI densification. The stripper plate similarly serves both as a compression tooling surface and as a gas flow path. This multi-functionality reduces the number of separate components needed.
2Reliability
If multiple fixtures are used for heat treatment and densification, then processing completeness is improved, but manufacturing time and productivity decrease
Solution Approach 1:
The needling process is performed while the preform is already positioned in the final tooling arrangement, before the CVI densification process. The textile needles pass through the perforations in the base plate and stripper plate during needling, preparing the preform structure in advance. This eliminates the need to move the preform to separate fixtures for subsequent densification, saving manufacturing time while ensuring complete processing.
Solution Approach 2:
The tooling arrangement enables continuous processing by maintaining the preform in the same fixture throughout both needling and CVI densification. The perforations remain open and accessible throughout the process, allowing seamless transition from mechanical reinforcement to chemical vapor infiltration without removing or repositioning the workpiece, thereby improving productivity.
3Strength
If through-thickness needling is performed, then interlaminar strength is enhanced, but process complexity and manufacturing time increase
Solution Approach 1:
The patent merges the needling and CVI densification operations into a single continuous process within the same tooling arrangement. The perforated base plate and stripper plate facilitate both needle passage for needling and gas flow for densification without requiring process interruption or fixture changes, reducing manufacturing cycle time while achieving through-thickness reinforcement.
4Manufacturing precision
If uniform densification is achieved through CVI, then material quality is improved, but process control complexity increases
Solution Approach 1:
The base plate and stripper plate feature perforations distributed across their surfaces, creating localized gas injection points throughout the preform. This distributed approach ensures uniform gas flow and consistent densification across different regions of the composite part. The perforation pattern can be optimized for specific geometric features, providing local quality control without complex overall system design.
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 tooling arrangement facilitates efficient through-thickness reinforcement and uniform densification of composite preforms, enhancing the interlaminar strength and thermal properties of the final composite parts, particularly suitable for high-temperature aerospace applications.
Implementation Method 1
Each perforation of the second plurality of perforations can be configured to receive the textile needle therethrough, whereby the textile needle penetrates through said perforation, through the fibrous preform, and at least partially through the corresponding perforation of the first plurality of perforations
Implementation Method 2
A preform tooling arrangement comprising a base plate with a male die surface and a stripper plate with a female die surface, both featuring perforations for textile needles, allows for through-thickness needling and subsequent chemical vapor infiltration (CVI) densification
Data Source
AI summary
A preform tooling arrangement includes a base plate comprising a male die surface and a stripper plate comprising a female die surface. A plurality of perforations are disposed in the base plate and/or the stripper plate. The stripper plate is moveable with respect to the base plate. The preform tooling arrangement is configured to receive a fibrous preform between the male die surface and the female die surface. The preform tooling arrangement is a dual-purpose fixture configured to accommodate z-needling and densification, all while the fibrous preform remains in the same fixture (i.e., the preform tooling arrangement). The perforations are configured to receive one or more textile needles for through thickness reinforcement of the fibrous preform.