Composite Friction Part CVI with Integrated ZrOxCy Densification
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Solution Overview
Problem
The existing process for manufacturing carbon/carbon composite friction parts with a zirconium ceramic phase is complex due to the separate stages of pyrocarbon densification and zirconium introduction, which complicates the manufacturing process.
Innovation Solution
A method involving chemical vapor infiltration using a second gaseous precursor, such as a C1 to C6 alcohol or polyalcohol modified with a zirconium group, to form a ZrOxCy phase within the pyrocarbon matrix, simplifying the densification process and reducing costs while maintaining performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If zirconium is introduced by liquid route after first stage of densification by CVI, then the friction part has good tribological performance, but the manufacturing process becomes more complex and time-consuming
Solution Approach 1:
The patent combines the zirconium introduction step with the pyrocarbon densification process by using a gaseous precursor containing both carbon and zirconium elements. This allows simultaneous formation of the pyrocarbon matrix and incorporation of zirconium species, merging two previously separate operations (densification by CVI and zirconium introduction by liquid route) into a single integrated process, thereby reducing manufacturing complexity while maintaining tribological performance
2Reliability
If zirconium is introduced by liquid route after first stage of densification by CVI, then the friction part has good tribological performance, but the manufacturing time is extended due to multiple loading and unloading cycles
Solution Approach 1:
The patent merges the zirconium introduction operation with the pyrocarbon densification operation by using a single gaseous precursor that delivers both carbon and zirconium. This integration eliminates the need for separate loading/unloading cycles required when using liquid route zirconium introduction, thereby reducing total manufacturing time while preserving the desired tribological properties
3Stability of the object's composition
If commercial zirconium-based precursors are used, then the ZrOxCy phase can be formed, but the cost increases and chemical stability decreases
Solution Approach 1:
The patent changes the chemical parameters of the precursor by selecting a gaseous compound containing both carbon and zirconium elements with appropriate volatility and reactivity characteristics. This parameter change enables the precursor to be introduced via gas phase CVI process, improving chemical stability during processing and reducing cost compared to commercial zirconium-based precursors, while still forming the desired ZrOxCy phase in the final composite
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 manufacturing process, maintains tribological performance and resistance to wear, and reduces the complexity of the process by integrating zirconium introduction into the CVI process, offering a more efficient and cost-effective method for producing friction parts.
Implementation Method 1
densification of a fiber preform made of carbon threads by a matrix comprising at least pyrocarbon (PyC) and at least one ZrO x C y phase, where 1 ≤ x ≤ 2 and 0 ≤ y ≤ 1, the matrix being formed by infiltration chemical vapor phase (CVI)
Implementation Method 2
a C 1 to C 6 alcohol or polyalcohol modified by binding oxygen atom of at least one alcohol function to a group of formula -Zr-R 3
Data Source
Figure 1~2
AI summary
The present invention relates to a process for manufacturing a composite friction component, comprising at least the following step: - densification of a fibrous preform made of carbon yarns by a matrix comprising at least pyrocarbon and at least one ZrOxCy phase, where 1 < x < 2 and 0 < y < 1, the matrix being formed by chemical vapor infiltration at least from a first gaseous precursor of pyrocarbon and a second gaseous precursor comprising zirconium, said second precursor being a C1 to Ce alcohol or polyalcohol modified by bonding of the oxygen atom of at least one alcohol function to a group of formula -Zr-R3, the R substituents being identical or different, and R being selected from: -H, C1 to C5 carbon-based chains and halogen atoms.