Ceramic Component Reaction Bonding for Complex CMC Assemblies
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Solution Overview
Problem
Large CMC components with complex geometry are difficult to fabricate in a single piece or at an acceptable yield, necessitating improved methods for joining densified ceramic components to form unitary ceramic components with unified construction.
Innovation Solution
The method involves positioning a braze reactant layer between densified ceramic components, applying a pack material, and heating to a braze temperature to react the infiltrate composition with the carbon source material, forming a ceramic material that integrates the components into a unitary ceramic component with a unified construction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If CMC components are fabricated in a single piece, then the component achieves unified construction, but the manufacturing complexity and difficulty increase significantly
Solution Approach 1:
The invention divides the complex CMC component into multiple densified ceramic sub-components that can be manufactured separately using conventional techniques. These sub-components are then joined together through reaction bonding to form the final unified structure, thereby reducing manufacturing complexity while maintaining structural integrity
Solution Approach 2:
The invention uses composite material structure where densified ceramic components are joined through a reaction bonding process that creates a metallurgical bond. The resulting structure combines the advantages of densified ceramics (high strength, low porosity) with the bonding process that creates a unified construction
2Strength
If conventional joining methods are used for ceramic components, then the components can be assembled, but the joint strength and reliability are insufficient
Solution Approach 1:
The invention changes the physical and chemical parameters during the joining process by heating to reaction bonding temperatures (1000-1600°C). This thermal parameter change enables the formation of strong metallurgical bonds between ceramic components, significantly improving both joint strength and reliability compared to conventional mechanical or adhesive joining methods
Solution Approach 2:
The reaction bonding process utilizes phase transitions where the infiltrate material melts and then solidifies to form a strong bond between ceramic components. This phase change enables complete penetration and metallurgical bonding, creating joints with superior strength and reliability
3Shape
If complex shapes are formed through ply layup processes, then the desired geometry is achieved, but the manufacturing process becomes overly complicated
Solution Approach 1:
Instead of forming complex shapes through multiple ply layup steps, the invention segments the component into simpler densified ceramic sub-components that can be manufactured using conventional techniques. The complex geometry is then achieved through the assembly and reaction bonding of these sub-components, significantly reducing process complexity
Solution Approach 2:
The invention performs preliminary densification of ceramic preforms into dense ceramic components before final assembly. This preliminary action simplifies the subsequent joining process and enables the formation of complex shapes through assembly of pre-densified components rather than through complicated ply layup processes
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 process allows for the formation of complex shapes without complicated ply layup processes, resulting in a unitary ceramic component with enhanced mechanical properties and suitability for high-temperature applications like gas turbine engines.
Implementation Method 1
heating the at least one infiltrate source, the pack material, the first densified ceramic component, and the second densified ceramic component to a braze temperature that is at or above a melting point of at least one phase of the infiltrate composition such that the at least one phase of infiltrate composition melts
Implementation Method 2
reacts with the carbon source material to form a ceramic material, the ceramic material joining the first densified ceramic component and the second densified ceramic component
Implementation Method 3
heating the at least one infiltrate source, the pack material, the first densified ceramic component, and the second densified ceramic component to a braze temperature
Data Source
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AI summary
Methods for forming a unitary ceramic component (110) are provided. The method may include: positioning a braze reactant layer (104) in a contact area (106) between a first densified ceramic component (100) and a second densified ceramic component (102); positioning a pack material (108) around at least a portion of the first densified ceramic component (100) or the second densified ceramic component (102); positioning at least one infiltrate source in fluid communication with the braze reactant layer (104); and thereafter, heating the at least one infiltrate source, the pack material (108), the first densified ceramic component (100), and the second densified ceramic component (102) to a braze temperature that is at or above a melting point of at least one phase of the infiltrate composition such that at least one phase of infiltrate composition melts and flows into the braze reactant layer (104) and reacts with a ceramic precursor compound therein to form a ceramic material.