Ceramic Matrix Composite Infiltration to Limit Void Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional reactive melt infiltration manufacturing practices for ceramic matrix composites (CMCs) result in void formation during re-working, repairing, or joining processes due to the drainage of alloy through capillary actions, leading to defects in already-infiltrated MI-CMC components.
Innovation Solution
The use of pre-saturated wicks and controlled infiltrant feedstocks with specific melting points and compositions to prevent alloy back-drawing, ensuring continuous alloy supply and minimizing void formation during secondary melt infiltration steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If conventional reactive melt infiltration manufacturing practices are used for re-working, repairing, or joining MI-CMC components, then the components can be re-worked or repaired, but void formation occurs due to alloy drainage through capillary actions
Solution Approach 1:
The wicks are pre-saturated with infiltrant material before the secondary melt infiltration process. This preliminary saturation ensures that the wicks contain sufficient alloy to supply the targeted area during repair or re-working operations, preventing alloy drainage and void formation in already-infiltrated regions.
Solution Approach 2:
Saturated wicks serve as intermediary material between the infiltrant source and the targeted area of the MI-CMC component. The wicks act as a controlled release mechanism, providing steady alloy supply through capillary action without causing drainage into already-infiltrated regions, thus preventing void formation.
2Quantity of substance
If alloy is supplied during secondary infiltration steps, then the targeted area can be re-infiltrated, but alloy drains through capillary actions causing void formation in already-infiltrated areas
Solution Approach 1:
The infiltrant material is locally concentrated in the saturated wicks positioned adjacent to or in contact with the targeted area. This localized saturation ensures that alloy is supplied precisely where needed during secondary infiltration, while preventing unwanted drainage into already-infiltrated regions, thus avoiding void formation.
Solution Approach 2:
The saturation level of the wicks is controlled and optimized to contain the appropriate amount of infiltrant material. By adjusting the saturation parameter, the system achieves balanced alloy supply to the targeted area while preventing excessive drainage that would cause voids in previously infiltrated regions.
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 effectively limits void formation in MI-CMC components by maintaining alloy saturation within the wicks, thereby enhancing the integrity and density of the components during re-working, repairing, or joining processes.
Implementation Method 1
The saturated wick is configured to deliver the molten infiltrant material to the targeted area
Implementation Method 2
a preform of fibers and matrix constituents is infiltrated with a molten material which produces a ceramic matrix when reacting with the matrix constituents
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A method (200) for limiting void formation in a melt-infiltrated ceramic matrix composite (MI-CMC) component includes arranging one or more infiltrant feedstocks (252) in fluid communication with a targeted area of the MI-CMC component. The one or more infiltrant feedstocks (252) have a nominal melting point at or below a nominal melting point of an alloy within the MI CMC component. The method (200) includes heating the one or more infiltrant feedstocks (252) to a first temperature at or above the nominal melting point of the one or more infiltrant feedstocks (252) to form a molten phase. The method (200) also includes infiltrating the targeted area of the MI-CMC component with the molten phase. As such, the molten phase reacts with a solid phase in the targeted area of the MI-CMC component. Further, the method (200) includes cooling the MI-CMC component to a second temperature that is below the first temperature to solidify the molten phase.