Carbon Composite Brazing With Metal Carbide Bond Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Carbon composite components in high-temperature applications, such as aerospace, face challenges in forming durable bonds with other components due to the inability of braze materials to stick and form robust bonds, often requiring mechanical fasteners which are undesirable in certain applications.
Innovation Solution
A method involving a high-temperature coating with a metal carbide bond layer on carbon composite substrates, allowing for bonding with braze materials without mechanical fasteners, using techniques like infiltration and brazing with platinum group metals, to create a strong and delamination-resistant bond.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If mechanical fasteners are used to join components to carbon composites, then the bonding strength is sufficient, but the device complexity increases and the structural integrity is compromised
Solution Approach 1:
The patent replaces mechanical fastening systems with a chemical bonding system. A metal carbide coating layer is applied to the carbon composite substrate, creating a chemically compatible surface that forms strong metallurgical bonds with braze materials, eliminating the need for mechanical fasteners and their associated complexity
Solution Approach 2:
The invention creates a composite structure consisting of the carbon composite substrate combined with a metal carbide coating layer. This composite surface structure combines the advantages of carbon composites (high temperature resistance) with the bonding capabilities of metal carbides, enabling direct brazing without mechanical fasteners
2Temperature
If conventional brazing is attempted on carbon composite surfaces, then the process temperature can be kept low, but the braze material cannot form robust bonds with the carbon surface
Solution Approach 1:
The metal carbide coating layer serves as an intermediary between the carbon composite substrate and the braze material. This intermediate layer is chemically compatible with both the carbon substrate and the braze material, enabling strong bond formation at lower temperatures that would otherwise be insufficient for direct carbon-braze bonding
Solution Approach 2:
The invention changes the surface chemistry parameter of the carbon composite by coating it with metal carbide. This parameter change transforms the surface from being incompatible with braze materials to being chemically compatible, enabling robust bonding without requiring extreme temperature increases
3Strength
If metal carbide is deposited on the carbon composite surface, then the bonding surface is improved, but the delamination resistance is reduced compared to carbide formed from the surface
Solution Approach 1:
The metal carbide coating is applied as a preliminary layer before brazing, creating a prepared surface that enhances bonding. The coating process is optimized to ensure adequate adhesion to the carbon substrate, and the subsequent brazing process further strengthens the interface, preventing delamination
Solution Approach 2:
The invention applies metal carbide coating locally to the bonding surfaces of the carbon composite components. This localized treatment provides the necessary bonding quality at the joint interfaces without requiring complete carbide conversion of the entire component, maintaining structural integrity while achieving reliable bonds
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
Enables secure bonding of components without mechanical fasteners, improving resistance to oxidation and stress distribution, suitable for high-temperature applications like aircraft brakes and hypersonic environments, by forming a robust and durable bond between carbon composite substrates and other components.
Implementation Method 1
A surface portion of a carbon composite may be converted by infiltration with a metal to form a bond layer which includes metal carbide
Implementation Method 2
A surface portion of a carbon composite may be converted by infiltration with a metal to form a bond layer which includes metal carbide
Implementation Method 3
The braze material may form a stronger bond with the bond layer which includes metal carbide layer than the surface portion of the carbon composite
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An apparatus includes a first component comprising a carbon composite substrate. A high temperature coating is disposed on the surface of the carbon composite substrate. The high temperature coating includes a bond layer of a metal carbide on the surface of the substrate. The apparatus includes a second component, and braze material joining the surface of the first component to the second component. In some examples, a brake assembly may include a rotor having a surface configured to interface with another component of the brake assembly. The brake assembly includes an insert joined to the surface of the rotor without a mechanical fastener, and the insert defines a tough mechanical contact surface configured to protect the rotor.