Method for producing SiC/SiC composite material
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Solution Overview
Problem
The existing method for producing SiC/SiC composite materials faces challenges in forming a sufficient interface layer inside the substrate, as BN coating through chemical vapor deposition is difficult and slow, leading to issues with composite properties and crack formation.
Innovation Solution
A method involving impregnation with a slurry containing flaky lubricant particles, followed by drying and bending to form a thin interface layer on SiC fibers, which allows for easier integration of the matrix and reduces crack formation, using techniques like CVI, PIP, or MI for matrix formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If BN coating is performed through chemical vapor deposition, then the interface layer is formed on fiber surfaces, but it is difficult to form a sufficient interface layer inside the substrate and the film formation is slow
Solution Approach 1:
The patent uses flaky lubricant particles as an intermediary substance that facilitates interface layer formation. These particles are impregnated into the substrate and then transferred to fiber surfaces through bending, acting as a mediator that enables internal interface layer formation without requiring slow vapor phase growth throughout the entire substrate.
Solution Approach 2:
The flaky lubricant particles are impregnated into the substrate in advance before the actual interface layer formation. This preliminary impregnation allows the particles to be positioned within the substrate structure, enabling subsequent transfer to fiber surfaces when the substrate is bent, thus preparing the pathway for efficient interface layer formation.
2Reliability
If vapor phase growth is performed to form an interfacial layer reaching inside the substrate, then composite properties are improved, but the film formation becomes slow
Solution Approach 1:
The patent replaces the slow vapor phase growth mechanism with a mechanical transfer process. Instead of relying on vapor deposition to penetrate and form interface layers throughout the substrate, flaky lubricant particles are mechanically transferred to fiber surfaces through substrate bending, dramatically reducing formation time while achieving similar composite properties.
Solution Approach 2:
The patent changes the formation mechanism from a thermal/vapor-based process to a mechanical transfer process. By altering the fundamental parameter of how the interface layer is formed (from vapor deposition to particle transfer through bending), the process achieves both internal penetration and rapid formation.
3Strength
If many steps are used to produce SiC fiber reinforced SiC composite material including BN coating and repeated impregnation, then material properties are improved, but the production process becomes complex
Solution Approach 1:
The patent combines the interface layer formation and internal penetration functions into a single step of flaky lubricant particle impregnation followed by bending. This merges what would traditionally require separate BN coating and internal treatment steps into one integrated process, reducing overall process complexity while maintaining material properties.
Solution Approach 2:
The flaky lubricant particles serve multiple functions simultaneously: they act as interface layer precursors on fiber surfaces, penetrate into the substrate interior, and facilitate subsequent matrix formation. This multi-functionality eliminates the need for separate treatment steps for each function, simplifying the overall production process.
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 enables the easy formation of a thin interface layer within the substrate, enhancing the composite's structural integrity and ease of shaping, while preventing crack formation and ensuring effective integration of the aggregate and matrix.
Implementation Method 1
an impregnation step of impregnating the substrate with a slurry containing particles of a flaky lubricant
Implementation Method 2
a drying step of drying out a solvent of the slurry from the impregnated body
Implementation Method 3
an interface layer formation step of bending the impregnated body, and transferring the particles of the flaky lubricant to surfaces of the SiC fibers while stretching the particles
Data Source
AI summary
A method for producing SiC/SiC composite material according to the present invention includes impregnating a substrate with a slurry containing particles of a flaky lubricant to obtain an impregnated body, drying out a solvent of the slurry from the impregnated body, forming an interface layer on surfaces of the SiC fibers by bending the impregnated body, and transferring the particles of the flaky lubricant to the surfaces of the SiC fibers while stretching the particles, and forming a SiC matrix inside the substrate on which the interface layer is formed. Since a thin interface layer of the flaky lubricant can be formed on the surfaces of the SiC fibers by transferring the flaky lubricant to the surfaces of the SiC fibers, the interface layer reaching inside of the substrate can be easily formed.